YUCAIPA -- At least eight people were killed and nearly two dozen were injured when a bus carrying a group from Tijuana overturned on its way back from Big Bear Lake on Highway 38 north of Yucaipa on Sunday night.

"It happened so fast I don't know how it all happened," said a passenger who declined to give her name. "This was supposed to be a good day out with my companions and then this happened."

Authorities reported that 15 people suffered major injuries and seven others had moderate to mild injuries.

Numerous 911 calls began to flood the California Highway Patrol and the San Bernardino County fire dispatch center around 6:30 p.m., reporting that a large bus had overturned and was blocking Highway 38 near the Mill Creek Ranger Station east of Mentone.

Both sides of the highway remained closed 2 1/2 hours after the crash and it was unclear when it would reopen.

Forty-three people including at least two children were involved in the crash -- 38 passengers plus the bus driver, and four others from two other vehicles, a pickup truck hauling a small cargo trailer and a compact car, authorities said.

Authorities initially reported 10 people were killed but were still assessing the crash scene late Sunday to get an accurate number.

A small bus from San Manuel Bingo and Casino was called to take some of the passengers to their friends and loved ones at various hospitals.

Those who were injured were taken to Redlands Community Hospital, Loma Linda University Medical Center, Arrowhead Regional Medical Center in Colton and other hospitals.

Among the agencies that responded to what was called a county-wide emergency were the San Bernardino County, San Bernardino and Redlands fire department, Cal Fire from the Highland station, the San Manuel Fire Department, the CHP, the Sheriff's Department and the U.S. Forest Service.

Reach Beatriz via email, call her at 909-386-3921, or find her on Twitter @IEBeatriz. Reach Kristina via email, or call her at 909-793-3221, or find her on Twitter @TheFactsKris.