MONTREAL - Transportation Safety Board investigators were meeting with witnesses Sunday to try and determine what caused a float plane to crash in northern Quebec killing two people on board.

The DHC-2 Beaver float plane crashed around 11 a.m. Saturday in a swamp two kilometres from the La Grande Riviere airport, not far from James Bay.

The pilot and one passenger died and all three surviving passengers were flown to a hospital in Montreal, two of them with serious injuries.

Quebec provincial police and TSB investigators were on the scene Sunday, examining whether pilot error or a mechanical problem caused the plane to crash shortly after takeoff. They were also planning to pull the wreckage out of the water.

The pilot worked for Nordair, a commercial and corporate airline that operates in the James Bay and Hudson Bay area.

Quebec provincial police spokesman Richard Gagne said at least two of the passengers were from Ontario.

Investigators determined Sunday the float plane had taken longer than usual to take off, before crashing soon after taking flight, said Transportation Safety Board spokesman John Cottreau.

The weather in the region was clear at the time of the crash.

The latest victims bring to 19 the number of people killed in four small plane crashes in Quebec since May - three of them involving float planes.

On May 19, a Cessna 172 carrying three men and a woman slammed into an embankment on a tiny island in the St. Lawrence River, killing all four occupants.

Two men died on June 4, when their float plane crashed into Lac Berte in northern Quebec. The craft was recovered from the bottom of the lake a month later.

Less than two weeks later, seven people died when a twin-turboprop Beechcraft King Air 100 went down shortly after takeoff from Quebec City's Jean Lesage Airport.

And on July 16, a DHC-2 Beaver slammed into a mountain in Quebec's Lac-Saint-Jean region, killing four people and injuring two others.

Two of the victims from that crash were laid to rest Saturday.

It was a deadly float plane crash in British Columbia in May that prompted the federal transport minister to order a review into the aircraft safety.

A single-engine Cessna travelling from Tofino to the Vancouver Island community of Ahousat inexplicably dived into the ocean, killing the pilot and three passengers.

Last month, John Baird ordered a review of potential safeguards to improve float plane safety, and a review of innovations such as pop-out windows and the mandatory wearing of safety vests to improve escape options from submerged float planes.

A study of previous float plane crashes has found that almost 70 per cent of the deaths were caused by drowning.

Cottreau said investigators looking into the latest crash in Quebec would take the previous plane crashes into account as part of their analysis.

"Part of the regular process for us in any investigation is to look back in the history and to check for trends," he said.

"If there's a trend we'll uncover it."

But he added it could take over a year before investigators were ready to make their findings public.