LEXINGTON, Ky. – A commuter jet taking off for Atlanta crashed just past the runway and burst into flames, killing 49 people before dawn Sunday and leaving the lone survivor in critical condition.

The cause of the crash wasn’t immediately clear, but the location of the wreckage raised questions about the runways at Blue Grass Airport and whether Comair Flight 5191 had been on a runway too short for that type of plane.

The plane crashed and burned in a field just off the end of the airport’s shorter runway, a 3,500-foot-long, unlit strip built at a V shape to the main runway. According to the Federal Aviation Administration, it would have been too short for the CRJ-200 regional jet.

“We don’t know which runway they were using,” Lanter said.

The plane went down at 6:07 a.m., about an hour before sunrise, said FAA spokeswoman Kathleen Bergen.

The fuselage was largely intact when rescuers reached the wreckage, and authorities said they were able to get one crew member out alive. But the county coroner described a devastating fire in the plane following the impact.

“We are going to say a mass prayer before we begin the work of removing the bodies,” Fayette County Coroner Gary Ginn said.

“They were taking off, so I’m sure they had a lot of fuel on board,” Ginn said. “Most of the injuries are going to be due to fire-related deaths.”

The crash was the country’s worst domestic airplane accident in nearly six years.

FAA spokeswoman Laura Brown said the agency had no indication that terrorism was involved in any way. Both flight recorders, which should help investigators determine what went wrong were found, Ginn said.

Lexington police spokesman Sean Lawson said investigators were looking into whether the plane had taken off from the wrong runway and discovered it too late. The main runway at Lexington’s airport is 7,000 feet long, while a daytime-only, general aviation runway is about 3,500 feet. Blue Grass Airport had been closed to flights the previous weekend for runway repaving but reopened Aug. 20.

That type of plane needed 4,500 feet to 5,000 feet before it lifts off, said Paul Czysz, professor emeritus of aerospace engineering at Saint Louis University.

Czysz said aerial images of the wreck indicate it was almost inconceivable that the airplane could have taken off on the longer runway because its nose is almost parallel with the shorter one. Also, trees at the end of the shorter runway were damaged, he said.

“Sometimes with the intersecting runways, pilots go down the wrong one,” Czysz said. “It doesn’t happen very often.”

The three-member flight crew aboard the plane was experienced and had been flying that airplane for some time, said Comair President Don Bornhorst. He said the plane’s maintenance was up to date. He would not speculate on what happened.

“We are absolutely, totally committed to doing everything humanly possible to determine the cause of this accident,” Bornhorst said.

In Atlanta, most of the passengers aboard the crashed plane had planned to connect to other flights and did not have family waiting for them there, said Rev. Harold Boyce, a volunteer chaplain at Hartsfield-Jackson airport.

One woman was there expecting her sister on the flight. The two had planned to fly together to catch an Alaskan cruise, he said.

“Naturally, she was very sad,” Boyce said. “She was handling it. She was in tears.”

The only survivor, believed to be the flight’s first officer, according to airport director Michael Gobb, was in surgery at the University of Kentucky hospital Sunday morning.

Bornhorst identified the three crew members as Capt. Jeffrey Clay, who was hired by Comair in 1999, first officer James M. Polehinke, who was hired in 2002, and flight attendant Kelly Heyer, hired in 2004.

The plane had undergone routine maintenance as recently as Saturday, Bornhorst said. Comair purchased that plane in January 2001, and all maintenance was normal as far as the information Comair had Sunday morning, he said.

The plane had 14,500 flight hours, “consistent with aircraft of that age,” Bornhorst said. Comair is a subsidiary of Delta Air Lines Inc. based in the Cincinnati suburb of Erlanger, Ky.

Investigators from the FAA and the National Transportation Safety Board were at the scene.

Outside the terminal lobby at midmorning, Paul Richardson of Winchester had come to the airport because he believed a friend from Florida was on the plane.

“He took the earlier flight so he could get back to family,” Richardson said. He said airport officials were taking friends and family on buses to the nearby hotel.

Two sheriff’s deputies guarded the entrance of a nearby hotel where family members of passengers were being brought.