A flat bus tire brought grumbles from the 37 nursing home patients fleeing Houston in anticipation of Hurricane Rita (search).

Then Edna Briant heard a rumble and the driver stopped a second time. But it wasn't another flat. Briant was sitting two rows behind the driver of the bus that would soon burst into flames, claiming 23 lives.

The driver checked outside the vehicle and apparently noticed a problem, perhaps seeing flames or smoke — and he looked worried.

He briefly conferred with aides and yelled for passengers to get off the bus and onto the shoulder of Interstate 45 (search).

An aide rescued Briant, who is 87 years old and confined to a wheelchair, by throwing her "on her shoulder or something," quickly putting her down on the ground and going back for more patients.

"I couldn't move, and I said, 'Please God, don't let my back be broken,'" Briant said. "I said, 'Get Claire!'"

Her 84-year-old sister Claire was still on the bus.

The sisters had already escaped one hurricane, evacuating from New Orleans to the Houston area ahead of Hurricane Katrina (search). Less than a month later, Hurricane Rita forced an evacuation from their Brighton Gardens (search) nursing home in Bellaire, Texas.

The bus, owned by Global Limo of McAllen, Texas, was their ride to Dallas and safety from a storm that loomed large but eventually only gave Houston a swat.

Gridlock traffic turned a trip of four hours on a typical day into a 15-hour marathon.

The bus went out of service in July after its registration expired. It was allowed back on the road to help because of a waiver signed last week by Gov. Rick P (search)erry to aid relief efforts.

According to federal records, drivers for Global Limo were ordered to stop driving five times in the last three years, mostly for infractions regarding bus logs. In 2004, the company was rated as "satisfactory," with no evidence of major safety problems in recent years, records show.

Johnny Ray Partain, a former Global investor, has fought a legal battle with its owner, James H. Maples. Partain warned a court in May the buses were poorly maintained and dangerous.

"I've driven those buses. I was complaining about the brakes," Partain said. "My attorney asked me if those buses are dangerous, and I said, 'Yes, somebody's going to get killed.'"

Partain said Global Limo lost its business charter twice within the past 16 months for failing to pay state franchise taxes. The company also filed for bankruptcy in February.

A man who answered the phone at Global Limo's offices said Partain has nothing to do with the company and denied Partain ever drove for it. He referred all other questions to a San Antonio attorney.

Tina Jones, a nurse at Baylor University Medical Center (search), was on her way to work about 6:30 a.m. when she noticed black smoke billowing from the bus ahead of her just south of Dallas in Wilmer.

The bus moved over to the right shoulder from the middle lane. The first explosion rocked Jones' minivan. Then, a second blast followed and fire erupted from the bus.

"The flames were just horrific. They were huge, especially it being so dark," Jones said. "It was so dramatic. It all happened so fast."

Jones yelled to a police officer that she was a nurse and the officer waved her through traffic.

Two off-duty paramedics from Wilmer, who chanced upon the accident, tended to the elderly people who escaped. Jones said she thought to herself, "There's got to be more people on this bus."

Of the 37 patients aboard, 14 survived. Of those, four were originally evacuated from New Orleans.

An investigation into the cause of the accident may last a year or more, said Keith Holloway, a spokesman for the National Transportation Safety Board (search).

Early indications were that mechanical problems, possibly with the bus' brakes, sparked the fire, which was then fed by the explosion of passengers' oxygen tanks, Dallas County sheriff's spokesman Don Peritz said.

Edna Briant survived, a deep purple bruise evident on her left arm. She told her story on Sunday from a nursing home in Dallas.

She sat in a wheelchair. A second wheelchair beside her supported her sister, Claire.

Two hurricanes, one explosion and two sisters survived.