A ceiling collapsed at a private prison in Texas Saturday injuring at least 19 prisoners and trapping many more, the Associated Press reported.

One of the injured inmates is in critical condition and had to be airlifted to Memorial Hermann Hospital in Houston. His name and condition have not been released.

Prison spokesman Issa Arnita said in a statement 18 inmates suffered cuts and bruises. However, officials at the prison said at least 10 prisoners were transported to a hospital by ambulance, suggesting their injuries were more severe than a bruise.

Authorities say a wallboard collapsed in one of the areas where inmates live at the 518-bed Diboll Correctional Center. Management & Training Corp. (MTC) operates the facility, which is about 100 miles northeast of Houston.

"We are still trying to determine the cause of the collapse," MTC said in a statement.

However, speculation indicated heavy rainfall could have been the cause.

"We got a lot of rain yesterday. It's a new building, a new facility. I don't know why the roof would collapse," Lufkin Fire Department Battalion Chief Jesse Moody told CNN.