SHERMAN, Texas — Like others returning from a religious festival in Missouri, Hoang Vu stopped at the spot where a charter bus carrying fellow Vietnamese Catholics on the pilgrimage had crashed and killed 17 people.

“It has actually strengthened our faith,” Vu said Sunday. “Now the whole world knows. So I think that God used this tragedy to strengthen our faith. I truly believe that.”

While Vu and others paused at a makeshift memorial at the site of Friday morning’s crash, federal authorities moved to shut down the companies that have been linked to the charter bus.

The Federal Motor Carrier Safety Administration ordered Iguala BusMex and Angel Tours Inc. to cease commercial operations. The agency issued a second order finding that the activities of Angel De La Torre, owner and president of the bus companies, “in connection with motor carrier operations pose an ‘imminent hazard’ to the public.”

Authorities also announced that an Iguala BusMex bus was pulled out of service at the religious festival in Carthage, Mo., because it was unauthorized to operate.

The voicemail service for Angel Tours’ remained full late Sunday.

Bus driver Barrett Wayne Broussard, 52, remained in critical condition at a Sherman hospital. No one answered the phone at his Houston home.

Broussard’s driving record includes citations for driving while intoxicated in 2001 and for speeding in May 2004 and March 2007. His license was suspended for two months in 2001 because of the DWI conviction in Harris County, said Debbie Hersman, a spokeswoman for the National Transportation Safety Board.

Broussard failed roadside inspections twice last year, Hersman said. Inspectors pulled his bus out of service both times.

Robert Accetta, the NTSB member leading the investigation, said an investigator will travel to Houston to learn more about the two bus companies.

Iguala BusMex applied in June for a federal license to operate as a charter but was still awaiting approval, according to online records. Angel Tours was forced by federal regulators to take its vehicles out of interstate service June 23 after an unsatisfactory review.

Inspectors are also looking at the mechanics of the wrecked bus and examining its interior damage, Accetta said.

Authorities said the vehicle’s right front tire, which blew out, had been retreaded in violation of safety standards. The bus skidded about 130 feet before striking a guardrail. It then traveled nearly 120 feet before coming to rest down an embankment near a creek.

The wreckage sits in the city impound lot. All the emergency windows on its right side are broken. Overhead bins on the right side appear to be collapsed. Some seats — all of which are still anchored to the floor, Hersman said — are warped toward the windows. The front right corner of the bus is smashed. All the wheels have been removed.

At the crash site along the Texas-Oklahoma border, travelers stepped from their cars or from buses on Sunday and placed candles, a wreath of flowers, and a cross and a card at the makeshift memorial.

Mourners gathered in a circle and sang a prayer for the victims. Some wept.

“I was pretty shocked when I heard about it because … there’s a lot of people that we know on that bus,” said James Tran, 28, of Houston. “So I’m thinking that could have been us and it made me realize that life is really short and precious and you never know when — you know — it might can happen to you.”

Portraits of five parishioners who died in the crash were displayed during Sunday services at the Vietnamese Martyr Church in Houston. The Rev. Vu Thanh told churchgoers they must accept the tragedy as a “door that God has opened.”

The crash in Sherman is among the nation’s deadliest. In 2005, 23 people were killed near Dallas when a bus carrying nursing home residents away from Hurricane Rita caught fire.