Investigators on Friday began to probe the cause of a commuter plane crash that killed 50 people outside Buffalo, New York, leaving a fiery scene of destruction.

Smoldering jet fuel at the scene held investigative teams at a distance while families agonized over what caused Continental flight 3407 to suddenly crash into a house in Clarence Center late Thursday after a flight from Newark, New Jersey.

The Bombardier Dash 8 Q400 exploded on impact around 10:20pm, about five minutes before it was due to land, shooting flames above nearby houses in a quiet town northeast of New York state's second largest city.

President Barack Obama offered his condolences to the families and friends of those killed, which included 49 passengers and crew on board and one person in the house.

"Michelle and I are deeply saddened to hear of the tragic accident outside of Buffalo last night. Our hearts go out to the families and friends who lost loved ones," he said in a statement.

Investigative teams from the National Transportation Safety Board were dispatched to the scene early Friday, a spokesperson said.

Emergency Coordinator David Bissonette told CNN that plane apparently dove into a house before bursting into flames and said the only recognizable part of the plane was the tail.

The last communication from the plane, aired on US media, gave no evidence of distress before air traffic controllers lose contact.

Controllers desperately tried to make contact with the pilot as the plane, run by Colgan Air for Continental, approached Buffalo-Niagara airport, also the tourist gateway to Niagara Falls.

One controller asked another plane to look for the missing flight and when he was told it could not be seen, he asked someone to contact police.

Continental and Bombardier, the maker of the plane, sent condolences to victims' families and said it had dispatched its own product safety and technical teams to the site to assist the NTSB investigation.

"Until such time as the investigators release any information or findings, Bombardier cannot comment further or speculate on the cause of this accident," the statement said.

"The fuselage of the plane lies directly on the footprint of the house," Bissonette said. "It basically dove right into the top of the house."

"It's remarkable that it only took one house, as devastating as that was. It could have easily wiped out that entire neighborhood in a streaking run type of thing," he said. Nearby homes suffered only minimal damage.

Erie County Executive Chris Collins told CNN the plane was carrying 5,800 pounds of jet fuel and turned into a fireball on impact.

FBI agent Laurie Bennett said evidence could not be collected until the scene was deemed safe, which could be several hours.

The Buffalo News reported that one of the victims was Beverly Eckert, whose husband was killed in the 11 September, 2001 attacks on the World Trade Center in New York.

"We know she was on that plane," her sister Sue Bourque told the paper, "and now she's with him."

Witness Tony Tatro told CNN that the plane flew right over his car, "nose down," and that the engine was making noises that "didn't sound typical."

"By the time that I had parked my car, literally, one block from where I made the 911 call and gotten out and gone through a yard it was a matter of minutes after impact and the home was completely destroyed already at that point," he said.

"Fully engulfed in flames, 12-15 meters high. The heat was intense enough you couldn't get to the same side of the street."

There was snow and sleet in the area at the time of the crash, which is normal for the area this time of year.

Continental Airlines pledged its full support to Colgan Air, "so that together we can provide as much support as possible for all concerned."