A bus carrying 15 prison inmates and staff plunged off a Texas highway overpass and onto railway tracks below, where it was hit by a train on Wednesday, killing 10 people.
"Two correctional officers and eight offenders have died from injuries sustained in the accident," a spokesman from the Texas Department of Corrections said in a statement, adding that five people were hurt.
"One staff member and four offenders have been transported to the Medical Center in Odessa and are receiving medical treatment," the statement said.
Jason Clark, director of public information for the Texas Department of Criminal Justice, told AFP that the accident occurred on a busy stretch of highway shortly after dawn, as the bus carried inmates from one prison facility in Abilene in western Texas to another in the city of El Paso.
"The bus left the roadway and made contact with the train," Clark said.
Officials said they did not know what caused the bus to leave the roadway, but said that visibility at the time was poor and the roadway was slick, with temperatures hovering around freezing.
"The conditions were less than favorable this morning," Sergeant Gary Duesler of the Ector County Sheriff's Department told AFP.
"For whatever reason, whether it was for icy conditions or whatever, it went down the embankment and into the path of an oncoming train," Duesler said.
Officials said the accident scene was horrific.
"It's as bad as you can imagine. In 32 years it's as bad as anything I've seen," Kavin Tinney, chief of a firefighter battalion, told the Odessa American newspaper.
Texas prison officials, who said an investigation was underway, lamented the loss of life.
"It's with a heavy heart that we mourn the loss of those killed and injured this morning in a tragic accident.
"Their loved ones will be in our thoughts and prayers," Brad Livingston, Executive Director of the Texas Department of Criminal Justice, said in a statement.
Duesler said sheriff's deputies worked to secure the scene as the investigation continued.
"We've got the road closed off because it's a major accident scene," he told AFP.
"There are some inmates that were transported to the hospital, and of course, they're still inmates, so we're providing security for them," he said.