All brakes on a tour bus that crashed in February near Yucaipa, killing seven passengers and another motorist, were defective, causing them to give out as the motorcoach careened down Highway 38, federal safety regulators said in a report released Thursday.

According to a review by the National Transportation Safety Board, investigators for the California Highway Patrol determined that "100 percent of the brakes" on the tour bus were defective in some way.

Investigators also determined that had the bus been stopped for a roadside inspection it surely would have been removed from service.

The charter bus crashed Feb. 3 just south of Yucaipa on the way back to Mexico after a day trip to Big Bear.

In recordings of phone calls to emergency dispatchers, one woman who called 911 at 6:32 p.m. said the bus crashed after it "passed up a line of traffic going about 80 mph."

"I don’t know what’s wrong with the person driving the bus," she told the dispatcher.

“OK, because their brakes went out,” dispatcher responded, according to recordings of the emergency calls related to the crash provided by the CHP.

Shortly before the crash, in January, the bus operator, Scapadas Magicas, was scheduled for an annual inspection. But the bus that crashed near Yucaipa was not presented for inspection, according to the NTSB.

The CHP found that each of the six brakes on the bus had at least one condition -- in most cases multiple conditions -- that would have caused each brake to be considered defective, the NTSB said.

On Thursday, NTSB Chairwoman Deborah A.P. Hersman used the Yucaipa crash along with three other high-profile incidents as examples to chastise federal regulators for lax oversight of the tour bus industry. 

The Federal Motor Carrier Safety Administration, Hersman said, needs to "crack down before crashes occur, not just after high visibility events."

"Our investigators found that in many cases the poor performing company was on FMCSA's radar for violations, but was allowed to continue operating and was not scrutinized closely until they had deadly crashes," she said.

The NTSB found that Scapadas Magicas had been deemed by regulators to be an "imminent hazard" and was slapped with an out-of-service order only after the deadly crash.

The other three crashes the NTSB cited on Thursday included one that killed nine people in Pendleton, Ore., in December 2012, a fatal crash in Elizabethtown, Ky., in March and another in Murfreesboro, Tenn., in June. 

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ari.bloomekatz@latimes.com