A freight train derailed while passing through the Howard Street tunnel in Baltimore, Maryland. One of the cars was punctured and the tripropylene it contained subsequently ignited. The fire, smoke, and fumes prevented entry into the tunnel for several days. Several theories were offered regarding the derailment. Based on wear damage present on a freight car side frame, one theory was that the train had already been derailed prior to entering the tunnel. The engineering analysis utilizing advanced wear and heat transfer techniques proved that the wear occurred within seconds of the derailment.
ESi also correlated the damage on the tank, brake components, and other parts to show how the tank was punctured. A civil engineering analysis was also performed on the tunnel structure, which took into account several water main failures had allowed over 14-million gallons of water to flood the tunnel, displacing sand and bricks into the tunnel. The multiple courses of brick, which created the tunnel, had bulged the wall and it was reported that water was seen shooting from a hole in the center of the bulge.