(CNN) -- Two people were dead and dozens of others were taken to hospitals after a charter bus bound for Oklahoma casinos crashed and overturned on a Dallas-area turnpike Thursday morning, officials said.
At least 36 people were transported to local hospitals after the crash on President George Bush Turnpike in Irving, Texas, said Dr. Paul Pepe, Irving Fire Department medical director.
At least three were in critical condition, Pepe said. Because many of the passengers were elderly, medical personnel are monitoring even those with minor injuries closely, said Pepe, who also is chair of emergency medicine at Dallas' Parkland Memorial Hospital.
The bus struck a barrier, "rode on top" of a concrete strip and hit the ground, coming to rest on its side, Department of Public Safety Sgt. Lonny Haschel told CNN affiliate KTVT. It was the only vehicle involved in the crash, he said.
The bus, owned by a Dallas-area charter company, was taking people to casinos in Oklahoma, said Nick Robison of Irving's emergency management office.
Video from KTVT showed a bus on its side, surrounded by numerous emergency personnel. Traffic on part of the toll road was halted as responders tended to the scene.
The National Transportation Safety Board said it has sent a team of investigators to the scene of the wreck.
IRVING (CBSDFW.COM) - Emergency crews responded to the scene of a overturned bus in Irving on Thursday morning. The incident happened shortly after 9:00 a.m. in the northbound lanes of the President George Bush Turnpike, near Belt Line Road. No other vehicles were involved in the crash.
"For an as yet undetermined reason, that motorcoach traveled off the righthand side of the roadway and struck what's called an impact attenuator, those big rubber things that are on the side of the road," explained Sgt. Lonnie Haschel with the Texas Department of Public Safety. "After it struck the impact attenuator, it went back across the lanes of traffic into a grassy area and struck the concrete median. It rode up on top of that concrete barrier and it rolled on its righthand side, where it came to a rest."
State Trooper Kyle Bradford said that over 30 people were on the bus when it crashed and one person was even trapped in the wreckage. "There was one individual that was pinned in. That individual has since been removed, still trying to confirm condition of that individual," he explained. "We do know that the individual that was actually pinned in is very serious at this time."
A total of 36 passengers were injured and have already been transported to area hospitals, including 9 victims taken to Parkland Hospital in Dallas by air ambulance. The others were transported by ground ambulance or Dallas Area Rapid Transit buses that arrived for assistance. Two people died, according to Texas DPS officials on the scene. Most of the victims are elderly.
"It was a pretty chaotic scene. There were a number of severe injuries when we first arrived," recalled Officer John Argumaniz with the Irving Police Department. "I don't think that you can ever prepare yourself for accidents like this."
Michael Rey with the North Texas Tollway Authority confirmed that it was a private travel bus that crashed. The bus belongs to Cardinal Coach Line from Mansfield. It was reportedly bringing tourists to Choctaw Casino in Durant, Oklahoma, just across the state border. On the company's website, they claim that all bus drivers are "qualified under all the current State and Federal D.O.T. rules and regulations." The company has experienced no crashes within the past two years and has earned ‘satisfactory' safety rating. They have only been in business since March 2007.
Authorities from the Texas DPS, the Irving Police Department, the Irving Fire Department and DART are working on the scene, with the Texas DPS taking charge in the crash investigation. "In this case, we declared that mass casualty. We alerted the other agencies. We alerted area hospitals to be prepared to receive these patients," said Assistant Chief Rusty Wilson with the Irving Fire Department. "And so, all of that comes together in a mass casualty like this. So, it's critical."
Traffic in both directions along the toll road has been shut down while crews are on the scene, and officials expect the road to remain closed until the investigation is complete. "It's going to be closed for quite some time," Haschel said. Check the traffic section for alternate routes, and stay with CBSDFW.COM for the latest updates.