A Mullin man was killed in a one-vehicle rollover accident on Monday morning, and three children were injured.

David Mangus, 34, was killed as his 2007 Chevy pickup ran off the road, rolled over and hit a tree roof-first, according to the Texas Department of Public Safety. The accident occurred 1.9 miles south of Mullin on FM 573 at about 7:30 a.m. Monday.

Mangus, who was wearing a seat belt, was pronounced dead at the scene.

Mangus’ oldest son, Dustin Mangus, 10, is in critical condition at Cook Children’s Hospital in Fort Worth. Sidney Mangus, 9, and John Carl Mangus, 7, were treated and released at Brownwood Regional Medical Center.

All of the occupants of the car were wearing seat belts.

The cause of the accident is still under investigation, but reports show the roads were wet at the time of the crash.

The accident is being investigated by Senior Trooper Stephen Douglas Lankart of the Lampasas DPS office.