Investigators trying to piece together the cause of Sunday's fatal Greyhound bus crash in Santa Maria say the 63-year-old driver, while he may have been fatigued, according to witnesses, did not break any law limiting the number of hours behind the wheel.

Preliminary reports indicate that Samuel Henry Bishop, who had driven the bus from Fresno to Los Angeles Saturday night and was scheduled for a route to San Luis Obispo, took a break between trips and did not violate the federal limit of driving more than 10 consecutive hours.

Bishop's bus crashed just after 7 Sunday morning on northbound Highway 101 just south of Betteravia Avenue in Santa Maria, killing two passengers and injuring all 42 others on board, some critically.

According to witnesses, the Greyhound had just passed a car at 65 mph when it veered off the right shoulder, tipped on its side, and skidded into a eucalyptus tree.

Killed were Martha Contreras, 23, from Santa Maria, who was seven months pregnant, and Faro Jahani, 50, a San Francisco businessman.

Contreras' husband, Augustin, was with his wife on the bus when it crashed just three miles from their destination. The fetus did not survive.

Injured passengers, including Bishop, were taken to hospitals in Santa Maria, Arroyo Grande, and Lompoc.

CHP officials are investigating mechanical failure as well as reports that Bishop may have fallen asleep.

Greyhound officials say they are extremely strict about overworked or tired drivers, who are ordered to immediately pull off the road at the first sign of fatigue.

Rosary services for Martha Contreras will be held Sunday, Dec. 4 at 7 p.m. at Dudley-Hoffman Mortuary. A funeral mass will take place Monday at 9:30 a.m. at St. John Neumann Catholic Church in Santa Maria with burial services to follow at Santa Maria cemetery.

-King Harris