British security forces deactivated what appeared to be a crude firebomb in a vehicle that crashed into a trash bin in central London's Haymarket district early June 29. If the device was intended to cause casualties as part of a militant plot, however, its amateur construction and the way it was placed suggest the plotter or plotters have no connection to a major militant organization. The incident began shortly before 2 a.m. local time when an ambulance crew, responding to a call about an injury at a nearby nightclub, noticed a Mercedes E-190 with what appeared to be smoke pouring out of it. Bouncers working the doors of nightclubs in the area reported that the vehicle was being driven erratically before it crashed it into the trash bin. Afterward, the driver and several other people reportedly fled the scene. Police called to the site cordoned off the area, while explosives experts examined the vehicle, finding what a police spokesman described as "a potentially viable" explosive device. Police manually disabled the device and later were seen removing gas canisters from the vehicle. The Mercedes reportedly contained several canisters of propane gas, a large amount of gasoline, nails — presumably to act as shrapnel — and a means to detonate the device. The amount of gasoline was so great that the fumes it emitted looked like smoke rising from the car. After the device was rendered safe, the vehicle was removed intact from the scene for a forensic investigation. It is unclear how much explosive material, if any, was recovered from the device. Although London Metropolitan Police counterterrorism chief Peter Clarke said early on in the investigation that the device could have caused "significant" loss of life had it detonated, several factors make this improbable. The device possibly was meant to be an explosive-actuated incendiary device. Such devices — more commonly called firebombs — work by using a relatively small low-intensity explosive charge to ignite a more volatile flammable material. This results in an intense, rapidly spreading fire that can quickly engulf a confined space such as a building, rail car, subway car or airplane. A firebomb would not be as dangerous in an open outdoor space like the one in this case. Furthermore, powerful explosive-actuated incendiary devices are extremely difficult to make, and getting the explosive charge to ignite the fuel is challenging. In many cases, the initial explosion merely hurls the tanks or otherwise fails to puncture the containers or ignite the gas — or it damages the tanks to the point that the gas leaks out harmlessly. The amount of flammable gas apparently recovered in this incident would have been sufficient to create a massive fireball, though in order for the device to reach its full explosive potential, it would have to have been carefully designed with a precise mixture of fuel and air. The bombmaker and the car's driver (assuming they are two people) erred in deploying the device. By crashing into the trash bin, the driver brought attention to himself and the vehicle, while the escaping gas fumes also called attention to the Mercedes. In any case, with so much forensic evidence remaining intact, British authorities have a good chance of identifying the culprit or culprits soon. Furthermore, the heavy closed-circuit TV coverage in London should allow authorities to obtain video and still photos of the would-be attackers. Initial reports of the discovery of a "massive" car bomb indicate the level of tension in London regarding potential militant plots. Coming on the heels of several high-profile terrorism convictions and arrests of suspected militants in the United Kingdom, this incident will serve to increase tensions — and vigilance — in London. Following the Haymarket incident, British police cordoned off another area in central London, Park Lane, to investigate reports of a "suspicious vehicle" believed to be connected to the Mercedes. Remarking on the incident, new Prime Minister Gordon Brown confirmed that the United Kingdom faces a "serious threat" from terrorism. Vigilance will likely increase in the rest of Europe as well. Before this, German authorities already were reporting elevated threats of militant attacks after receiving intelligence from U.S. authorities.