DENVER -- Unnamed sources “familiar with early data gathered” told the Wall Street Journal that Continental flight 1404 crashed Saturday evening at Denver International Airport after a problem with the plane’s brakes.

Passengers on board the plane say they felt it take off and then come back down and crash into a 40-foot deep ravine.

Another source has told 7NEWS investigator that Tony Kovaleski wind shear is to blame.

"At this stage in the investigation, wind sheer or a large guest of wind are the most probable causes of the crash," the source, who refused to be identified because they were not authorized to speak publically about the investigation, told Kovaleski.

The weather was cold but not snowy when the plane took off on a flight to Houston around 6:20 p.m. Saturday. The airport did report wind gusts, but it is unclear if the plane was hit by a gust of wind.

Speculation is flowing on the Professional Pilots Rumor Network.

One post wondered if the pilot forgot to extend the flaps (moveable parts of the wing that are designed to provide extra lift during takeoff and landings). “Watch this space, think there is something more to this story, Crew forgetting to set the flaps NOT to be ruled out yet,” HighLow wrote.

Many of the posts included images and analysis of the downed plane from news Web sites.

A pilot who said he landed in Denver five minutes before the crash said there was ice on the runway. “Does sound like an inopportune wind gust will be one of several suspects,” pattern_is_full wrote.

Aviation expert James Simmons said reports of debris on the runway could have caused the crash.

“The discussion about debris or the runway possibly before the plane lifted off could possibly indicate their was a problem with the aircraft. If so, my guess is that it most likely was an engine problem,” Simmons said.

But anyone looking for answers were quickly disappointed by a Sunday 3 p.m. news conference by the National Safety Transportation Board.

“We are just now beginning our investigation,” said Board Member Robert Sumwalt. He refused to speculate about any causes of the crash saying the mission of the 15-member Go Team is to collect “perishable evidence, the information that may go away with the passage of time,” he said.

NTSB investigations are notoriously long. It took almost four years for the NTSB to issue a final conclusion in their investigation of TWA flight 800 which exploded in midair killing 230 people.

“We want to take as long as it takes to be able to do the job right, so that when we do have a determination of probable cause we are confident we are doing it based on facts and good through analysis,” Sumwalt said.

Both the flight data recorders and cockpit voice recorder have been recovered and are said to be in “good condition.”

They have been taken to Washington D.C. where they will be played as early as Sunday night.

Sumwalt said the Go Team will begin taking their measurements on Monday and work from sunrise to sunset.

When asked if the location of the crash site, so close to the airport and resources, will speed their investigation, Sumwalt said it does increase their chances of a successful investigation.

The damaged plane would remain for several days in the 40-foot-deep ravine where it landed. That runway will remain closed during the investigation, he said.

Back on the rumor network, Continuous Ignition writes that wind is a likely suspect. Looking at images of the plane, he said it looks like the flaps were down after all.

“How that plays into the accident, who knows.. Lets wait to see what the NTSB says... Should be interesting none the less."