Armando Lopez, 25, and his mother, Rachel Hughes-Lopez, died at the scene near Southern Avenue and Hawes Road, police said. The crash was reported about 4:30 p.m. Friday.

According to police, Armando Lopez was behind the wheel of the sedan involved in the collision. Early indicators suggest he was speeding before impact, authorities said.

The driver of the school bus was taken to a hospital in critical condition, according to fire officials. Police said Monday they had no update on the driver's condition.

No children were aboard the bus when the crash occurred, police said.

The intersection of Southern Avenue and Hawes Road sits in a busy stretch of east Mesa, where a school bus route and commuter traffic share the roadway during the afternoon dismissal window. The fact that the bus was empty at the time spared students from being caught in the collision, though the severity of the injuries to the driver underscored how quickly a routine route can turn dangerous.

A former school bus driver who knew the injured driver came to the scene to see the wreckage for himself, describing the crash as a shock to those who work the routes.

Police have not announced any citations or charges and said the investigation is continuing. They asked anyone with information about the collision to contact the department.

The deaths mark at least the second serious traffic incident involving pedestrians or vehicles in Mesa in recent weeks, following a Halloween night crash that injured several children. Traffic safety advocates have repeatedly urged drivers to slow down on arterial roads like Southern Avenue, where posted limits and school-route traffic can shift quickly.

Funeral arrangements for Hughes-Lopez and her son were not immediately available.