fire of the Mont Blanc tunnel
1999 CE.
Shown on the map at 45.859°, 6.908°.
On 24 March 1999, a transport truck caught fire while driving through the Mont Blanc Tunnel between France and Italy. When it stopped halfway through the tunnel, it violently combusted. Other vehicles in the tunnel quickly became trapped and caught fire as firefighters could not reach the transport truck. 39 people were killed. In the aftermath, major changes were made to the tunnel to improve its safety.
Text from the Wikipedia article Mont Blanc Tunnel fire, licensed CC BY-SA 4.0.