AUSTIN, Texas (AP) — Dash camera video released Thursday by a Texas school district shows the moment a cement truck veered into oncoming traffic, hitting a school bus carrying more than 40 pre-K students returning from a zoo field trip.

The deadly collision on March 22 sends the bus rolling over on a rural highway outside Austin. The video released by the Hays Consolidated Independent School District shows papers from the bus strewn across the road and other drivers leaving their cars to race toward the bus.

A 5-year-old boy aboard the bus and a driver in another vehicle were killed. Others aboard the bus were airlifted to hospitals or transported by ambulances.

Eleven adults were also aboard the bus.

The crash remains under investigation. Authorities have not said how fast the vehicles were traveling.