A Texas state trooper says the driver of a charter bus involved in a deadly rollover crash remains hospitalized with major injuries and has not been interviewed by police, the Associated Press reported.

Sgt. Johnny Hernandez did not release the name of the driver and said Sunday that investigators are still searching for a cause of the crash.

Hernandez said the Department of Public Safety is conducting an investigation separate from the National Transportation Safety Board.

The OGA Charters bus crashed Saturday north of Laredo, Texas, killing eight and injuring 44 others. Officials say the deceased ranged in age from 52 to 61.

The medical examiner in Webb County in South Texas has released the names of the eight people killed in a rollover charter bus crash.

The victims were identified as Altagracia Torres, Maria de Jesus Musquiz, Dora Nelly Gonzalez, Frances Guerrero, Marisela Lopez, Adelfa Garza, Jaime Navarro, and Emma Rodriguez Zamudio.