One person was killed and several were injured after a bridge collapsed in southwest France on Monday, according to the Haute-Garonne fire brigade and police.

A 15-year-old girl died after the bridge leading to the small town of Mirepoix-sur-Tarn collapsed at 8 a.m. local time, Toulouse prosecutor Dominique Alzeari said. The girl’s mother was rescued by witnesses at the scene. Three vehicles were caught in the bridge collapse, according to the prosecutor.

Haute-Garonne police said three people were seriously injured in the incident, including witnesses who tried to help the victims.

Among the injured are also two of the 67 firefighters who rushed to the scene, police said. A total of 40 police officers, as well as divers, were sent there.

“We will do our best to find anyone who is missing,” Haute-Garonne police chief Étienne Guyot said.

An investigation has been opened into the cause of the bridge collapse.