The probe into the crash of Continental Flight 3407 in suburban Buffalo in northern New York state is going to be a long process and the actual cause of it remains unclear at this stage, a spokesman for the National Transportation Safety Board (NTSB) said Saturday.

Firemen walk towards the site of a plane crash to remove the wreckage of the plane in Buffalo of New York State, the United States, on Feb. 14, 2009. Investigators on Saturday morning continued their probe into the crash of Continental Flight 3407 in suburban Buffalo. The 50-seat commuter plane was flying from Newark to Buffalo when it crashed into a home in Clarence Center at around 10:20 p.m. on Thursday (0320 GMT Friday), killing all 49 people on board and another person on the ground. [Xinhua]

Addressing a press conference at a hotel miles away from the crash site, Steven Chealander gave an update on the fiery crash of the 50-seat commuter plane en route from Newark to Buffalo on Thursday night, killing all 49 people on board and another person on the ground.

Investigator on Saturday continued to sift through the rubble at the crash site in an effort to recover the remains of the victims and the remnant of the airplane.

But the recovery process was slowed down a little bit in the morning because of ice that had formed at the site, obviously a result of the large amount of water used by fire-fighters trying to put out the fire.

Local policemen cordon off the site of a plane crash in Buffalo of New York State, the United States, on Feb. 14, 2009. [Xinhua]

Workers had to bring in heaters to blow warm air into the site to thaw out the frozen rubble before recovery efforts went on.

Currently there are about 100 to 150 people working at the scene, with FBI agents, local medical and law enforcement personnel and fire-fighters comprising the bulk.

Chealander described the recovery efforts as a difficult "excavation process," typically because the wreckage of the plane intermingled with that of the house, which was burnt down to the ground.

Three to four days are required to recover the victims' bodies before DNA and dental tests can be made to determine their identities, he noted.

According to a plan by the NTSB, whatever is left of the airplane will be separated from the remnant of the house and be moved to another yet unknown location for further investigation and analysis.

(Xinhua News Agency February 15, 2009)