On 15 August 1944 French B-26 Marauder bombers and American B-17 Flying Fortresses of the 42nd Bomber Wing tried to destroy the railway bridge and the road bridge which span the Durance in Sisteron. The weather was unfavorable and the bridges were not destroyed. A bomber during a manoeuvre to avoid a collision accidentally dropped several bombs on the town. including a full church, causing about 100 fatalities and seriously damaged the citadel. On August 17, the French aircraft returned and destroyed the bridges.