YUCAIPA, Calif. (AP) - Federal and state investigators are searching the mangled wreckage of a tour bus for the cause of a weekend crash that left seven people dead and injured dozens of others.

Authorities targeted the brakes and other equipment on Tuesday for clues to why the driver lost control on a two-lane mountain highway in the San Bernardino Mountains on the way home from a trip to the snow.

The roadworthiness of the 1996 bus loomed as a key issue after the driver told investigators the brakes failed as he descended from the popular ski area of Big Bear.

Federal records point to a history of brake-maintenance problems with the European-made bus.

Launching a review that could take months, investigators for the California Highway Patrol and NTSB began collecting evidence on the bus, road conditions and possible driver error or fatigue that could have played a role in the crash.

The bus was carrying 38 people, including the driver and a tour guide, when it left Tijuana, Mexico, at 5 a.m. Sunday for a daylong trip.

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