Historical perspective

The first VBIED attack in the United States was the Wall Street Bombing of 1920 by Italian anarchist Mario Buda. Although not on a motorized vehicle, Buda drove his horse-drawn wagon filled with 100 pounds of dynamite and 500 pounds of cast iron shrapnel into the heart of the financial district in New York City. He dismounted the wagon and walked away. The wagon-based VBIED exploded, killing 38 and wounding 143 people.

The first VBIED using a motorized truck was used in what is still America’s worst school massacre: the 1927 attack in Bath, Michigan. Andrew Kehoe, angered over a property tax levied to pay for the Bath school, conducted a tiered VBIED/IED attack that set the stage for the future use of improvised explosives in terrorist attacks. In the months preceding the attack, Kehoe staged two 500-pound piles of dynamite and pyrotol in the basement under the north and south wings of the building. He set the devices to explode simultaneously with timers. On May 18, 1927, the timer-detonator triggered an explosion under the north wing. Fortunately, the other charge failed to detonate because of mechanical failure of the second timer. After murdering his wife and firebombing his farm, Kehoe drove to what was left of the Bath Consolidation School in his pickup truck rigged with explosives and extra metal pieces to use as shrapnel. When he arrived, Kehoe called the superintendent over to his vehicle, detonated his VBIED, and killed four more individuals, including another child. In all, this lone wolf killed 38 children and 6 adults, including himself. In addition, he wounded 67 other children and teachers, making this one of the most devastating domestic attacks in U.S. history, excluding the 9/11 attack.

In both these historic bombings, the attackers used a high-order explosive to disperse heavy shrapnel and cause injuries. Kehoe, America’s first suicide bomber, also employed the same explosives to cause a building collapse in a multibomb attack. Kehoe’s attack portended the modern terrorist deployment of VBIEDs.

Extremists in the Middle East use VBIEDs extensively. Terrorists quickly realized that the capacity and power of the VBIED explosion itself was more destructive than the shrapnel it could create. In Beirut, Lebanon, on April 19, 1983, a bomber drove a truck with 2000 pounds of explosives into the U.S. embassy, killing 63 people. This highly successful attack on the embassy led by the Islamic Jihad Organization encouraged the next attack on the U.S. Marine barracks soon after, on October 23 of that same year. At 6:22 in the morning, a truck disguised to look like a local water delivery truck, but loaded with 12,000 pounds of explosives enhanced with large tanks of butane gas, smashed through a flimsy fence of concertina wire in between two guard posts. The truck smashed into the floor lobby of the Marine barracks. Within seconds, the driver detonated the truck-based VBIED, causing seven floors of concrete reinforced with one and three-quarters steel rebar to heave upwards, while the building support columns, measuring 15 feet in diameter, were sheared in half. Due to the building’s design and the fact that the vehicle had penetrated so deeply into the structure, a tamping effect of the explosion caused the building to implode onto itself. The collapsed seven stories filled the 8-foot-deep crater measuring 39 feet long by 30 feet wide.

The resulting blast was so powerful that it shattered all the windows of the air traffic control tower of the Beirut International Airport over half a mile away. The Federal Bureau of Investigation (FBI) reported that at that point the blast was the largest nonnuclear explosion seen on earth. Investigation by the FBI revealed large quantities of unburned pentaerythritol tetranitrate (PETN) at the blast site. PETN is not an HME and is produced by a nation-state only for the production of military-grade explosives. Lebanon lacked this capability and Iran was implicated as the main supplier of explosives and training for the bombing of the Marine barracks. This gigantic blast was undoubtedly a win for the Islamic Jihad Organization, who later evolved to operate under the name Hezbollah. The United States withdrew its marines from Lebanon the following February due to the collapse of the supported Lebanese government. Many experts attribute this withdrawal at least partially to the devastating VBIED attacks on U.S. assets and personnel.

The bombing of the Marine barracks served as a template for many extremists in the following years. Attackers took advantage of the lack of sufficient perimeter security and demonstrated, with terrible consequences, the destructive capacity of VBIEDs on community infrastructure. The attack on the Alfred P. Murrah Federal Building in Oklahoma City on April 19, 1995, was the most devastating VBIED attack in America at the time. The attack wounded 680 people and killed 168, including 19 children. Timothy McVeigh parked his 24-foot Ryder moving truck just 16 feet from the building, with approximately four devices composed of 5000 pounds of ANFO. The truck detonated and sheared the concrete support beams. The building suffered a major failure of a girder designed to transfer weight. As a result, successive floors collapsed, creating a complex technical urban search and rescue (USAR) response environment. Most of the deaths were due to crush and blunt trauma associated with the collapsed area of the building. The injured and those that were initially extricated from the collapse zone were transferred to receiving facilities via ambulance. During the response, local emergency management services (EMS) had activated “on call” personnel and executed mutual aid agreements with surrounding departments to handle the patient transport load. Many victims with minor injuries were transported via private vehicle and presented to local hospitals in a delayed fashion. This was in part due to the large response from bystanders that swarmed the bombing site to help. Bystander response created a logistic problem for incident command, because the collapse zone was unsecure and unsafe. Bystander presence, in this case, subsequently factored into the 14 additional injuries and 1 fatality suffered during the rescue response.

The Oklahoma City Bombing offers several lessons learned for response to VBIED attacks. First, a majority of the deaths were due to building collapse, causing crush injury, massive head trauma, and torso trauma. In addition, a majority of the survivors suffered from head injuries and orthopedic injuries. Structural collapse is the most lethal aspect of a VBIED attack against a building. There are several ways a structure can collapse, and typically VBIEDs have caused a “pancake” collapse where the floors fall on top of each other. Any collapse scenario is complicated and requires time, special equipment, and highly trained personnel in order to respond effectively. These aspects combined with any security issues associated with a bombing site add to the extended rescue time frame and mortality of trapped victims. As a result, VBIED attacks on fixed structures create the potential for complex trauma patients with a mix of penetrating, blunt, and blast pathology, combined with inhalational insults and exacerbation of underlying comorbidities. Second, VBIED attacks can create significant infrastructure damage; in Oklahoma City buildings were damaged up to 16 blocks from the blast site. This devastation can affect response routes (e.g., roads), communication (e.g., loss of cell towers), and coordination. Finally, given the tendency of bystanders to flock to attack sites, the risk of follow-up attack is high.

Ramzi Yousef’s February 26, 1993, attack on the World Trade Center (WTC) in New York City demonstrated terrorists’ commitment to expanding and evolving their use of VBIEDs. Yousef parked a truck VBIED packed with 1300 pounds of explosives in the basement parking lot of the north tower of the WTC. Yousef and his coconspirators intended to destroy foundation columns of the north tower, causing it to topple into the south tower. This first attack on the WTC resembled techniques used in Beirut, but failed for a variety of technical reasons. The most striking similarity was the use of a gas enhancement of the main charge. In the WTC case, the bombers arranged canisters of hydrogen gas around the main charge of urea nitrate to increase the magnitude of the blast. This use of gas enhancement is commonplace in the military and creates a thermobaric effect that releases an immense amount of energy, heat, and rapidly expanding pressure. The thermobaric effect is especially lethal in confined spaces, such as buildings.

The following investigation and associated arrests in the WTC Bombing also revealed a new aspect to VBIEDs. Along with bomb-making materials, the FBI uncovered a very large amount of sodium cyanide. Yousef denied its use in the WTC bomb but did admit to contemplating its use in the bomb. This new tactic of combining chemical warfare agents and VBIED dramatically complicates first response to VBIED attacks. During Operation Iraqi Freedom (OIF), extremists built upon Yousef’s failures, adding chlorine canisters to VBIEDs and attacking both military and civilian targets.

The technique of using multiple or simultaneous VBIEDs in coordinated attacks first gained international notoriety after the bombings of the U.S. embassies in Nairobi, Kenya, and Dar es Salaam, Tanzania. The deadlier of the two attacks was in Kenya. Terrorists equipped with small arms and a VBIED (i.e., Toyota Dyna small haul vehicle) attempted to force their way through the embassy gate and enter the underground parking garage. Their access was blocked and they detonated the VBIED in the rear parking area of the embassy. Despite being outside of the physical structure of the embassy, the area devastation was immense. Although the embassy did not collapse, many of the 44 deaths in the embassy were associated with the secondary blast effects from shattered glass and displaced office furniture. The effects of blasts on surrounding local buildings included major structural damage (or collapse, in the case of the Ufundi building). In addition, the secondary blast effects on pedestrian traffic accounted for another estimated 200 deaths and 4000 wounded. The bomber was not as successful in Dar es Salaam, where the entrance to the embassy happened to be blocked by a water tanker. The bomber detonated his vehicle at the gate entrance, killing 12 and wounding another 85. In both instances the embassy security personnel were ill-prepared for repelling the attack, nor able to physically impede the vehicles by barriers or heavy gates, resulting in an environment for successful attacks. The sequencing of VBIEDs in two different countries continued to follow a trend of larger, far-reaching operations being undertaken by Al Qaeda (AQ) and associated terrorist networks. Both the 1993 WTC Bombing and the dual attacks at American embassies in 1998 seemed to be dress rehearsals for the 9/11 attacks.

Modern terrorists are displaying a tendency to deploy smaller VBIEDs. Passenger car–size bombs employed against targets of opportunity in the general public may be the new path taken by extremists, versus a large-scale target such as a building. On May 1, 2010, Faisal Shahzad, who was a naturalized citizen from Pakistan, left his parked car in a busy area of Times Square in New York City with the engine running and his hazard lights on. He had rigged several different explosive components into his Nissan Pathfinder to include M-80 fireworks, gasoline, three 20-pound propane tanks, and a metal box containing 250 pounds of urea-based fertilizer. Local street vendors noticed popping sounds and smoke coming from within the car. Two local street vendors alerted police, who evacuated and cordoned off the area. Although his device was a failure, it could have been a very devastating attack within any city in America. Similar attacks using incendiary and propane components were seen earlier in London in 2007, creating a noteworthy tactical trend that should be planned for by responders.

Terrorists will continue to have distinct advantages when deploying VBIEDs due to the availability and accessibility of various types of targets. Aggressors actively conduct surveillance on targets and often rehearse undetected beforehand. Active planning, preparation, awareness, and assessment of vulnerabilities for high profile sites are paramount for a good defensive posture. As seen in historical events such as the Beirut and Oklahoma City Bombings, VBIEDs are most effective close to or underneath buildings. In these circumstances, the use of barricades is the most effective countermeasure against a VBIED blast. The casualty-producing potential of a VBIED is equally as high in areas crowded with pedestrians. Unfortunately, these open environments are hard to safeguard. In planned mass gatherings, leaders can limit vehicle access and create tiered, highly regulated entry protocols. However, as seen in the successful Wall Street Bombing and the failed Times Square bombing, an attack can happen on any street in America. Reproduction or variations of any of these attacks will continue to create difficulty for responding municipalities, due to the variability of injuries, blast damage to surrounding infrastructure, and logistical aspects of response.