CHICAGO (AP) – Chicago police say two officers likely didn’t see or hear a train that fatally struck them as they pursued a suspect because they were looking at a train approaching from another direction.

Police spokesman Anthony Guglielmi said Tuesday that footage was recovered from the body camera worn by one of the officers killed Monday night . The officers were struck as they investigated a report of gunshots on the city’s far South Side.

Guglielmi says the video shows the officers “clearly acknowledge” a northbound train just before they were hit by a southbound train. He says the sound of the northbound train likely made it impossible for the officers to hear the other train.

Chicago Police Superintendent Eddie Johnson led a delegation of police command staff searching the area overnight. They recovered the remains of Officers Eduardo Marmolejo and Conrad Gary.