WILLIAMS, Calif. -- A mourning son is speaking out after his mother and seven other people were killed in a Colusa County bus crash.

Dozens of peole were also injured in the wreck on Sunday night and the driver of the casino-bound bus, Quintin J. Watts, is now under arrest on suspicion of driving under the influence.

"We are so sad," said Doua Vang, whose 68-year-old mother, Lou Her, was among those who died in the wreck. "We are so angry we lost our mom."

Vang added that he spoke to his mother by phone just moments after the crash, which took place along two-lane Lone Star Road near Williams. The bus was carrying 43 people, many of them Asian senior citizens from Sacramento who hoped to try their luck at Colusa Casino.

Vang said his mother was trapped in the bus as he spoke to her.

"She keep saying (the) same thing: 'I get stuck. I can't get out. Nobody help me. Nobody pull me out'," he recalled.

Injured passengers were taken to hospitals around the region. As of Tuesday, seven of the injured were at UC Davis Medical Center in Sacramento. Three were listed in serious condition, while four have improved to fair condition, a hospital official said.

An off-duty sheriff's deputy said he saw the northbound 1993 MCI bus swerving along the rural road just moments before it flipped and landed in hip-deep mud near a rice field.

Investigators said Watts, 52, has a history of traffic violations. Watts, who was hired by stepfather Daniel Cobb, was in his first day on the job when the bus crashed. Cobb was on the bus and also died in the wreck.

Others who died in the wreck are:

Xee Vang, 85, of Sacramento

Muang Saephanh, 68, of Sacramento

Khou Yang, 67, of Sacramento

Meuay Saelee, 74, of Sacramento

Fin Saechae, 64, of Sacramento

Ma Vang, 60, of Sacramento

The names of two other people who died have not yet been released.

Authorities were investigating whether prescription or nonprescription drugs or alcohol, or a combination, were involved in the crash.

Blood test results are not expected for two to six weeks.

State Department of Motor Vehicles records show that Watts had been cited for speeding and other violations that resulted in the loss of his license for nearly two years.

Watts regained his driving privileges last January.

Watts had a commercial license but was not cleared to transport 10 or more people by himself.

In 1981 and then 1983, Watts served time for receiving stolen property, and again in 1996, for check fraud and credit card theft.

In 1998, he spent more than a year in prison for possession of marijuana for sale and possession of a destructive device.

His latest conviction was for possession of a firearm by an ex-felon. He was paroled in Dec. 2007 after almost six months in prison, according to the state Department of Corrections and Rehabilitation.

He was a longtime truck driver, but had been unable to find a trucking job since being released from jail, his mother said.

Watts also served prison time for allegedly threatening his ex-wife last year at her Stockton apartment.