(Editor's note: This article has been updated throughout.) 

TIOGA — Two people were seriously injured and one horse was killed Wednesday afternoon following a multi-vehicle accident in Tioga.

The wreck, which occurred at the intersection of U.S. Highway 377 and Buck Creek Road, began when a southbound semi hauling building materials hit a pickup truck waiting to turn east on Buck Creek. The pickup was then forced into oncoming lanes, where it collided with a blue Chevy sedan. Both vehicles came to a rest on Hwy. 377. Following the initial impact, the semi traveled past the other two vehicles and into oncoming lanes where it struck another pickup hauling a horse trailer. The semi detached the horse trailer before leaving the roadway and overturning. The pickup truck hauling the trailer escaped major damage and came to a rest on the shoulder.

“As of this time, there are no (human) fatalities,” Tioga Police Chief Curtis Macomb said. “There are some serious injuries. Their current condition is serious, but, other than that, I don’t know anything else about their conditions.”

The male driver of the first pickup struck and female motorists in the sedan were both transported by air ambulance from the scene to Medical City Plano. Macomb said the male driver of the semi and the two occupants of the trailer-carrying pickup did not sustain major injuries and were not hospitalized.

Emergency officials from the Tioga Police Department, Texas Department of Public Safety, Grayson County Sheriff’s Office, Gunter Police Department, Pilot Point Fire Department, North Shore Fire Department and Tioga Fire Department all responded to the scene. Traffic on Hwy. 377 was halted in both directions and diverted while crews removed the wrecked vehicles and cleared the roadway of debris.

Macomb said the collision caused extensive damage, but said the outcome would likely have been far worse if the wreck had occurred just several hundred yards further south on a bridged portion of Hwy. 377 that crosses Lake Ray Roberts.

“This was a serious accident,” Macomb said. “We’re fortunate that it didn’t occur on the bridge because, as you can tell by the impact of the vehicles and the location of the vehicles, if it had been on the bridge we would have been in the water. We’re fortunate that people are alive.”

The Tioga police chief said the investigation into the collision is ongoing and encouraged motorists to always use caution when driving and to be sure that all occupants wear a seat belt.