Cause of Dynamic Airways Fire at Fort Lauderdale Airport Undetermined, NTSB Says

— -- The National Transportation Safety Board has not determined if a fuel leak was the cause of a jet fire at the Fort Lauderdale Airport on Thursday, officials said today.

The Dynamic Airways plane, a Boeing 767 bound for Caracas, Venezuela, caught fire while taxiing for departure at the Florida airport, according to the Federal Aviation Administration. One of the pilots on the plane following it reported that fuel was leaking from the aircraft before the fire started.

But it's unknown as of yet what caused the plane to catch fire, NTSB investigator Tim LeBaron said at a news conference this afternoon, adding that it's also unknown if the fluid seen coming from the jet was fuel.

LeBaron said the NTSB will look at the airplane systems to try to determine what the fluid was.

The NTSB investigators, who have been on the site since about noon today, will also investigate maintenance records and the flight crew, LeBaron said.

Airport officials said earlier today there was an estimated 45 to 50 gallons of fuel leaked on the taxiway, but emphasized that no fuel leaked onto the runway.

"We're in the process of repairing the taxiway," Airport Director Kent George said today during a morning news conference.

George also said there was "no fire in the cockpit, in the airplane itself."

"There was fire on the left wing and the number one engine," he said.

About 21 people of the 101 on board were injured, authorities said.

Passengers Andres Gallegos and Giorgio Serloni told ABC News a chute opened on the side of plane with the fire, and a few passengers went down just 10 feet from flames. They said some crew members were visibly panicked.

There were 90 passengers and a crew of 11, the airline said, also noting that the captain has 15,700 hours of flying time, which is considered experienced.

Dynamic hailed the response of its crew, saying, "The actions of the cabin crew were exemplary and according to their safety training." Dynamic said this plane, which is nearly 30 years old, was up to date with all maintenance requirements.

According to ABC News aviation analyst John Nance, "There's nothing wrong with flying a 25- or 30-year-old 767 as long as your maintenance is up to speed."

The FAA said the aircraft hadn't suffered any accidents or incidents prior to Thursday's fire, and according to the airline, the plane passed safety, mechanical and operation pre-flight inspections before departing the gate.

One of the pilots conducted a visual inspection of the plane prior to push back from the gate -- a standard procedure -- said the airline.

The plane also went through a very thorough inspection in June, the airline said.

Dynamic is a 6-year-old airline that operates six 767s. According to Nance, after this crash, Dynamic Airways may be under the microscope because it is a young airline.

"There's going to be a lot of scrutiny on this airline," he said, "as to whether they're up to speed on maintenance, and how ... their records are."

In addition to the NTSB, the FAA, Boeing, Dynamic Airways, and engine maker Pratt & Whitney are also involved in the investigation.