2018 Borgo Panigale explosion

The collision involved a liquefied petroleum gas (LPG) road tanker, another articulated lorry carrying flammable solvents, and a car transporter. It took place on the northbound carriageway of the ramo Casalecchio (Casalecchio branch) of the A14 motorway, which connects the A1 motorway to the A14 main route, within Borgo Panigale, a neighbourhood of Bologna, Italy. The stretch of motorway where the collision occurred crosses a densely populated area in the outskirts of Bologna and is flanked on both sides by the Tangenziale di Bologna, or Bologna ring road. Luckily, many businesses were closed due to the summer holidays. The crash occurred at 1:44 pm. The cause of the collision is unknown. Cameras captured the tanker heading straight into the preceding vehicle, which possibly eliminates the hypothesis of mechanical failure, because steering and brakes would have needed to fail at the same time. The driver was complying with all applicable rest regulations and speed limit. The tanker pressure vessel was also mechanically sound. The amount of LPG in the tanker was estimated at 23 or 25 tonnes. == Initial fire and BLEVE ==

The cargo of the rear-ended lorry ignited immediately, which resulted in a large pool fire engulfing the affected vehicles. The pressure vessel of the LPG tanker did not breach as a direct consequence of the crash. However, it was surrounded by flames from the pool fire. The vessel was not fire-proofed nor did it have a relief valve. Neither arrangement is required by Italian regulations or in the international ADR agreement. Seven minutes and 20 seconds after the collision, the tank failed due to loss of mechanical properties caused by external heating. This resulted in a massive BLEVE. == Aftermath ==

Given the tremendous thermal radiation, people within a radius of from the exploded road tanker would have died or received major injuries. The explosion sent fragments hundreds of meters away Buildings were damaged as far as away. Fires were extinguished two hours after the explosion. The road tanker driver died on the spot upon the first collision. A second victim died on 14 August. Thirteen among those hospitalized were policemen (11 carabinieri and two from the Polizia Stradale, or the Italian highway patrol). Prime minister Giuseppe Conte visited the injured at the Ospedale Maggiore in Bologna, where most of the wounded had been hospitalized, and the burn unit in Cesena. The other burn victims had been transported to the Parma burn unit. == References ==