Rescue workers attend the scene of the Turkish Airlines plane that crashed on approach to Amsterdam's Schiphol airport on Wednesday. (Peter Dejong/Associated Press)

Officials in the Netherlands warn that the death toll may rise after a Turkish Airlines flight crashed and broke into three parts while trying to land at Amsterdam's Schiphol Airport on Wednesday, killing nine people.

Pilots of the Turkish Airlines aircraft, top to bottom, were Hasan Tahsin Arisan, Olcay Ozgur and Murat Sezer. All three were killed. The plane slammed into a muddy field while attempting to land at Amsterdam's main airport on Wednesday. (THY/Associated Press)The plane's two pilots and an apprentice pilot who was accompanying them in the cockpit were among those who died, officials said.

Six people were critically injured and may not survive, while 25 others were in serious condition, airport and medical officials said during a news conference at the airport.

Twenty-four more people suffered minor injuries and all passengers were receiving counselling.

Officials don't know the cause of the crash of Flight 1951, which happened around 10:30 a.m. local time in cool temperatures and a light mist.

Pieter van Vollenhoven, head of the Dutch Safety Authority investigating the cause, said it appeared the plane lost speed before crashing.

"You see that because of a lack of speed it literally fell out of the sky," he told NOS radio after visiting the crash site.

By nightfall Wednesday, investigators had recovered the Boeing 737-800's flight data recorders and set up floodlights around the wreckage to help with what appeared to be a recovery effort, the CBC's Adrienne Arsenault reported.

The U.S. National Transportation Safety Board is sending a team of investigators to Amsterdam to assist the Dutch probe.

Plane 'broken in half': witness

The plane, which left Istanbul's Ataturk Airport earlier Wednesday morning, had 134 on board.

Witness Jonathon Yip told Radio-Netherlands he heard what sounded like a "small earthquake" about 300 metres from where he was standing, then a slew of emergency vehicles and helicopters racing to the scene.

"It looked like the plane was broken in half," he said.

A photo from the scene showed the Boeing 737-800 split into three parts, with a large chunk of the back section missing.

The plane, with a large crack in the fuselage behind the cockpit, lay in a muddy field about 300 metres short of a runway, in view of a nearby highway.

The aircraft's front and middle sections appeared intact, but the two engines were torn off and were about 100 metres from the fuselage.

Most of the plane ended up just 200 metres away from the busy highway, the CBC's Arsenault said.

Candan Karlitekin, head of the airline's board of directors, told reporters in Turkey that visibility was good at the time of landing.

Visibility good before crash: officials

"Visibility was clear and around 4,500 metres. Some 500 metres before landing, the plane landed on a field instead of the runway," he said.

Selahattin Alpar, Turkey's ambassador to the Netherlands, told the state-run Anatolia news agency there were 72 Turks and 32 Dutch people on board. There was no information on the nationality of other passengers.

Canadian consular officials in Ankara and The Hague are in contact with local authorities, but don't know yet whether any Canadians were on board, said André Lemay, a spokesman for Canada's Foreign Affairs Department.

"There are no known Canadian casualties or injuries at this time and the Canadian embassies are monitoring the situation closely," André Lemay said.

Four Boeing employees traveling on business were aboard the plane, according to Jim Proulx, a spokesman for the company. All four are based in the Seattle area, he said, but he would not provide further details until their families had been notified.

Proulx said Boeing was sending a team to provide technical assistance to Dutch safety officials as they investigate.

Plane dropped suddenly: survivors

Passenger Mustafa Bahcelioglu told CBC News everything appeared to be progressing normally with the landing until the plane suddenly dropped.

Rescue workers move injured passengers from the crash site. (Peter Dejong/Associated Press)Bahcelioglu, who was sitting in a seat near the wings, said passengers then felt a "big impact." He got out of the plane through the exit doors over the wings and helped six others get off the plane.

He said it all happened within seconds and there was no pilot announcement.

"I'm alive and I can see my child again," said Bahcelioglu, who is being treated in a local hospital.

NTVMSNBC, a 24-hour news broadcaster in Turkey, interviewed passengers who said the plane's tail appeared to hit the ground before it lost control. They said there was panic and screaming on board.

Another passenger told Turkish newspaper Hurriyet that some passengers thought the plane hit severe turbulence.

Mud may have absorbed impact

Turkish Transport Minister Binali Yildirim said it was "a miracle" there were not more casualties.

"The fact that the plane landed on a soft surface and that there was no fire helped keep the number of fatalities low," he said.

According to experts, the muddy, plowed field may have contributed to making the accident less deadly by absorbing much of the force of the hard impact. It may also have helped avert a fire resulting from ruptured fuel tanks and lines on the underside of the fuselage, which appeared to have suffered very heavy damage.

There were conflicting casualty accounts after the crash. Turkish Airlines initially said one person had died, but Karlitekin later told reporters there were no confirmed deaths.

Boeing's 737 is the world's best-selling commercial jet, with more than 6,000 orders since the model was launched in 1965. The 737-800, a recent version of the plane, has a "very good safety record," said Bill Voss, president of the independent Flight Safety Foundation in Alexandria, Va.

"It has been involved in a couple of accidents, but nothing that relates directly back to the aircraft," he said, adding that the plane had the best flight data recorders, which should give investigators a rich source of information about the crash.

With files from the Associated Press