DALLAS -- Dallas Fire-Rescue crews are investigating after a patient got behind the wheel of an ambulance and crashed it into a warehouse.

It all began Tuesday just after 6 a.m. when Dallas police say they received two calls from West Mockingbird Lane saying a man had been hit by a car. The second call was about a man acting strange.

First responders arrived on the scene and saw Dennis Walker, 49, covered in blood. When they tried to put him into the back of their ambulance, he ran into the driver's seat and took off.

Police say Walker drove through an open gate of a business called Dallas Foundation Drilling near Plantation and Harry Hines, then crashed into a warehouse.

Walker then got out of the ambulance and ran toward a yard crew vehicle down the road. The crew inside the car jumped out and took the keys as the suspect got inside.

Walker was taken to Parkland Memorial Hospital with minor injuries, police say. He is charged with theft and violating his parole.