MOUNT VERNON - A explosion rattled windows and alarmed people in Mount Vernon overnight.

Police say the loud bang was the result of a fire around 3 a.m. on the Metro-North tracks under the overpass at the intersection of West 1st Street and South 6th Avenue near the Mount Vernon East station.

Officials say the fire was sparked by road salt dripping on to the third rail from the street and bridge above.

The fire was put out quickly and service on Metro-North was not affected.