The driver of a rig containing 11 m³ of gasoline and 22 m³ of diesel lost control of his vehicle upon approaching the Mathilde Bridge at 10:45 am on the D6028 local highway. The trailer crossed the central guardrail and hit a refrigerated lorry travelling in the opposite direction. The fuel released by the torn tanker ignited, flowed and spread the fire to cable paths running under the bridge deck, as well as to 5 semi-trailers and 3 merchants’ caravans parked downslope. Iridescence was visible on the SEINE. Destroyed phone cables below the bridge affected service for 110,000 cell phone users. A 600-mm wastewater pipe was also damaged.

The Prefecture’s crisis unit was convened. Traffic was stopped and deviated, with the media relaying warnings to users. The bridge power supply (for lighting) was interrupted. First responders administered care to the 2 injured drivers as well as to 4 merchants and a police officer, who had sustained a hand injury. Waterway navigation was halted on the arm of the PRE-AU-LOUP. The Regional Health Agency informed the bridge operator of an adjacent potable water source. The Prefecture recommended that local residents remain indoors due to the thick smoke. The fire was extinguished by 6:30 pm.

The fire disturbed road traffic (10 km of backup on the N28, N31 and N15 highways, closure of the Grand’Mare Tunnel) and damaged the metal and prestressed concrete bridge structure, resulting in its 22-month closure to complete repair works (disassembly of a 115-m span to refurbish a 40-m length). The closure of such a major traffic corridor (86,000 vehicles/day) necessitated adopting a special department-wide transportation plan. The phone technician deviated his utility’s network via another bridge (3-km detour) and re-established service on 1 November.

The rig’s excessive speed in the turn leading to the bridge was responsible for this accident.