At least eight people were killed and 45 injured early Monday after a train slammed into a double-decker bus in Atlacomulco, northwest of Mexico City.

The deadly collision occurred in an industrial area filled with warehouses and factories. According to officials, the bus was attempting to cross the tracks amid heavy traffic when the train struck, dragging it several meters before finally stopping.

Video shared on social media shows the crossing lacked barriers or warning signals. Other vehicles had crossed the tracks moments before the crash. The force of the impact tore the roof off the bus, leaving passengers on the upper level exposed as the train pushed the wreckage forward.

Authorities in the State of Mexico said emergency crews remain on the scene, working to recover victims and assist the injured. The cause of the accident is under investigation.