A wreck that killed two truck drivers and spilled hundreds of gallons of raw sewage onto a Bastrop County highway Wednesday was caused by a tire blowout, officials said Thursday.

Department of Public Safety officials said that George Center, 37, of Austin was driving a UPS truck south on Texas 95 and that Larry Goodwill, 52, of Bastrop was driving a sewage truck north at 4:45 p.m. about four miles south of Elgin. A tire blew out on the front passenger side of the UPS truck, causing Center to lose control and enter the northbound lane, where the two trucks hit head-on, killing both men.

Raw sewage, oil and fuel spilled onto parts of the two-lane highway, causing it to be shut down for about five hours Wednesday evening.

The wreck damaged up to 3,000 square feet of the highway and surrounding area, said John Hurt, a spokesman with the Combined Transportation Emergency and Communications Center in Austin. He said that about 300 gallons of raw sewage was spilled. Some liquid quickly soaked into the ground, he said, but a residue that remained on the ground should be cleaned up by today. Hurt said UPS could be responsible for the cleanup cost, which has not been estimated because officials have not finished investigating the damaged area.

Center had been a fill-in UPS driver for about four years, said Susan Rosenberg, a company spokeswoman. She said the delivery company has begun its own investigation into the wreck. “Certainly it is a loss to the UPS family, and we have made outreach to his family,” Rosenberg said.

Goodwill owned Larry’s Septic Tank Service and also was the volunteer pastor at Church of the Risen Savior in Bastrop, said his daughter, Wendy Goodwill Christian. She said he was married for 33 years and known for his hard work and integrity.