The death toll has risen to 17 in the crash of a Texas charter bus carrying a Vietnamese Catholic group to an annual pilgrimage in Missouri.

The unlicensed bus smashed into a guardrail and skidded off a highway early Friday morning near the Texas-Oklahoma border. Twelve people died at the scene and four more have died at area hospitals. Officials said the remaining passengers and bus driver were injured.

One of the three crash victims brought to Methodist Dallas Medical Center died Friday evening, hospital spokeswoman Kathleen Beathard said. The hospital's other two victims, both men, remain in critical condition.

Click here to see photos.

The bus was carrying 55 people from Houston to Carthage, Mo., for an annual festival honoring the Virgin Mary. Most of the passengers were from the Vietnamese Martyrs Church and two other mostly Vietnamese congregations in Houston.

The Marian Days pilgrimage, which started in the late 1970s, attracts thousands of Catholics of Vietnamese descent and includes a large outdoor Mass each day, entertainment and camping at night.

Lt. Bob Fair of the Sherman Police Department declined to release the names of the dead because some family members have not been notified.

The vehicle's right front tire, which blew out, had been retreaded in violation of safety standards, said Debbie Hersman, a member of the National Transportation Safety Board. The tread had separated from the tire itself in a process called delamination.

"If there is a loss of pressure or the tire becomes delaminated, it's much more difficult to control the vehicle," she said.

It is legal to retread such tires but they may not be used on the wheels that steer the bus, Hersman said.

The 52-year-old driver had a commercial license but his medical certification had expired, she said. The driver was reported in stable condition at a hospital.

The bus operator, Iguala BusMex Inc. of Houston, had applied in June for a federal license to operate as a charter but was still awaiting approval, according to online records.

The company recently filed incorporation papers, listing the same owner and address as Angel Tours Inc., which was forced by federal regulators to take its vehicles out of interstate service June 23 after an unsatisfactory review, records show.

The review cited the company for problems in three areas: using a driver before receiving a pre-employment result, failing to require a driver to prepare a vehicle inspection report and using a driver who wasn't medically reexamined every two years.

Neither entity is authorized to operate as a carrier in interstate commerce, said John H. Hill, administrator for the Federal Motor Carrier Safety Administration.

At a Houston building with a weathered Angel Tours plywood sign, a man declined to identify himself Friday or comment to The Associated Press about the wreck. An outgoing phone message at Angel Tours said the voicemail box was full.

Vu Pham, 35, of Houston, said his brother, sister-in-law, mother and 12-year-old nephew all were on the bus. His brother, whose left leg has been paralyzed from polio since he was a boy, remained in intensive care Saturday in a Sherman hospital, he said.

"We thought it would be better for him to get on the bus because it's a far drive," Pham said. "Now he keeps saying that he should have driven himself."

Pham said his family feels lucky. None of his relatives are in critical condition, he said, "but we feel it could get worse."

"It's still a lot," he said. "You just take it one day at a time."

Like passengers around her, Leha Nguyen, 45, had started to doze off when she heard the bus make a horrible noise, followed by screaming. She opened her eyes to see people strewn about, one of them underneath a fallen television.

"I think I'm the luckiest one out of most people," she said.

It was the nation's deadliest bus crash since 2004, when 15 people were killed in a wreck in Arkansas on their way to Mississippi's casinos. In 2005, 23 people were killed near Dallas when a bus carrying nursing home residents away from Hurricane Rita caught fire in bumper-to-bumper traffic.

About 900 people gathered Friday night at Vietnamese Martyrs Church for a Mass attended by Cardinal Daniel N. DiNardo.

"We are here with them to pray for those who are lost and for God's consolation in this time of grief and loss," DiNardo said. "The Vietnamese Catholic culture is very strong. A lot of those who have come here have been through a great deal just to get to this country. They've always preserved their Catholic faith. This is a trial. This is a challenge."

DiNardo said the losses, which include church leaders, are "incomprehensible."

One of the victims was identified as Hoangy Thi Dung, 71, of Houston, who was pronounced dead by a Grayson County justice of the peace.

Organizers of the festival in Missouri said the victims would be remembered at Mass and at various conferences during the gathering.

Click here for more from MyFOXDFW.com.