TUXTLA GUTIERREZ, Mexico (AP) — Mexican authorities say at least 49 people were killed and dozens more injured when a cargo truck carrying what appeared to be Central American migrants rolled over and crashed into a pedestrian bridge in southern Mexico.

The head of the Chiapas state civil defense office says the preliminary estimate lists 49 dead and 58 injured. He says about 40 of the injured have serious wounds.

It is not unusual for freight trucks in Mexico to be carrying so many people in migrant-smuggling operations in southern Mexico.

The crash occurred Thursday on a highway leading toward the Chiapas state capital. Photos from the scene show victims strewn across the pavement and inside the truck’s freight compartment.