Three people were killed and 18 others were injured Saturday when a bus rolled over in Pala Mesa, California, according to the North County Fire Protection District. The accident occurred around 10:30 a.m PST.First responders arriving at the scene found the bus on its roof and in danger of sliding down an embankment, Captain John Choi of the NCFPD told CBS News affiliate KFMB. The bus needed to be stabilized before rescue crews could begin getting people out of the vehicle. According to Choi, the bus did not have seat belts. No other vehicles were involved in the accident.All three people who died were adults, according to North County Fire Chief Stephen Abbott. The other passengers were taken to multiple hospitals with varying degrees of injury. Five were taken to Inland Valley Hospital, five were taken to Palomar Hospital and eight were taken to Temecula Valley Hospital, Choi said. None of the victims have been identified.