A bus whose driver lost control around 6 a.m. on Monday on a highway near Acambay, México state, slid into a ditch leaving seven people people dead.

At least some of the victims were ejected out the bus’s windows and into the ditch, according to authorities. Among them was a pregnant woman. The media outlet UnoTV reported that other victims were also crushed underneath the bus, which rolled over into the ditch on its side.

Four surviving passengers with serious injuries were transported to a hospital in Acambay.

A host of state and local emergency personnel responded.

The bus, which belongs to the Omex VIP company and was traveling from Saltillo, Coahuila, was only about an hour from its final destination in Toluca when the accident occurred on the Aculco–Acambay highway near the community of Dongu.

Some initial media reports said that there were over 30 people on the bus, and at least 10 additional passengers received medical treatment at the scene but authorities told the newspaper Milenio that those reports were incorrect and that only 11 passengers and two drivers were involved in the accident.

Sources: Milenio (sp), El Sol de Toluca (sp), UnoTV (sp)