HOUSTON — A witness says the driver of a pickup truck that collided with a church minibus in rural Texas, killing 13 people, acknowledged he had been texting while driving — highlighting the dangers of sending messages on smartphones while behind the wheel.

Texas Department of Public Safety Sgt. Conrad Hein wouldn’t comment Friday on whether texting might have played a role in the Wednesday collision on a two-lane road about 75 miles west of San Antonio, near the town of Concan. But officials said the truck driver appeared to have crossed the center line.

Jennifer Morrison, the investigator in charge of the team from the National Transportation Safety Board, would only say that distracted driving will be among the issues investigated.

The witness, Jody Kuchler, a 55-year-old self-employed welder, told The Associated Press he and his girlfriend were driving back to their home in the nearby town of Leakey when he came across a truck that was driving erratically across the road.

“He kept going off the road and into oncoming traffic and he just kept doing that,” said Kuchler, who first shared the account of what happened with the San Antonio Express-News.

Kuchler, who followed the truck for at least 15 minutes, said he called the sheriff’s offices for both Uvalde and Real counties and told them “they needed to get him off the road before he hit somebody.”

Kuchler said he witnessed the crash and afterward, he checked on both the bus and the truck and was able to speak with the driver of the truck, who the Department of Public Safety has identified as 20-year-old Jack Dillon Young of Leakey.

“He said, ‘I’m sorry, I’m sorry. I was texting.’ I said, ‘Son, do you know what you just did?’ He said, ‘I’m sorry. I’m sorry,”’ Kuchler recalled.

Texas is unusual in that it has no statewide ban on texting while driving. Laws in 46 other states ban sending or reading email, using apps or engaging in other use of the Internet while driving.

Twelve people on the bus died at the scene, authorities said. Another died at a hospital. One bus passenger remains hospitalized in serious but stable condition.

Young, the driver of the pickup, also remains hospitalized.