Isaiah Guajardo, 21, of Jourdanton, was traveling in the eastbound lanes on state Highway 72, about 4 miles from Interstate 37, when his 2005 Mustang was struck by a Bell Supply Company tool trailer.
The trailer broke free from a white Chevrolet pickup, traveling in the westbound lanes, according to Department of Public Safety Trooper Gabriel Llamas.
As the trailer careened into oncoming traffic, its hitch hit the left rear tire of the Mustang and ripped it off, sending the Mustang sideways into the ditch, according to Llamas.
Llamas said witnesses to the accident said the trailer had hit a bump and started swaying back and forth until it became unhitched.
The driver of the Chevrolet pickup, Ricardo Cruz, 21, of Asherton, was uninjured.
Guajardo sustained injuries to the neck and back, according to Llamas. But he appeared not to have life-threatening injuries.
He was first transported by Acadian EMS to a heliport near the intersection of Interstate 37 and state Highway 72. Then he was flown by helicopter to Christus Spohn Memorial in Corpus Christi.