A westbound intermodal crosses the Stone Bridge (a semi-misnomer--the upstream side has been concrete since 1929) in Johnstown. Built in 1887-8, this is the bridge broke the wave that came crashing down the valley when the South Fork Dam broke on May 31, 1889. The debris carried by the flood jammed against the bridge, creating a temporary dam that caused the floodwaters to backwash into what is now downtown Johnstown instead of carrying on downstream towards Cambria City. The wall of debris then ignited and burned for 3 days, killing those trapped within.