GOLIAD, Texas -- At least 11 people died Sunday and another 12 were injured after their pickup truck left the highway and crashed into trees in a rural South Texas community, authorities said.

State troopers and Goliad County sheriff’s investigators were investigating what prompted the crash and have not released names of the victims. The Ford F-250 pickup was heading north on U.S. 59 when it struck two large trees Sunday evening in the unincorporated community of Berclair, about 100 miles southeast of San Antonio, said Gerald Bryant, a spokesman for the Texas Department of Public Safety.

DPS said a dozen people were taken to various hospitals in San Antonio, Victoria, and Corpus Christi. Bryant said several of the surviving victims had life-threatening injuries. He did not have their conditions, but said he believed them to be “very serious.”

The agency said 23 people, including some children, were in the vehicle.

“It’s been very chaotic here, and it’s very traumatic,” Bryant told the San Antonio Express-News. “It’s only first responders out here, and it’s very solemn.”

Crash investigators were still at the scene late Sunday night assessing the crash, which halted traffic on U.S. Highway 59.