A floatplane belonging to a fishing lodge crashed during takeoff Tuesday in southwest Alaska, killing three people and injuring the other seven on board, authorities said.

The injured passengers were being flown to Anchorage hospitals following the crash near the small community of Iliamna, 175 miles southwest of Anchorage.

Five people were badly hurt, including some critically, and two others sustained minor injuries, National Transportation Safety Board Alaska Chief Clint Johnson said.

Alaska State Troopers said the three dead were from outside the state but didn't know about the others. Rescue personnel initially took injured passengers to a local clinic.

Johnson said the plane belonged to the Rainbow King Lodge. Calls to the business went unanswered.

The plane crashed on takeoff at Eastwind Lake, a mile north of Iliamna, Federal Aviation Administration spokesman Allen Kenitzer said in an email to The Associated Press. It was a De Havilland DHC-3 Turbine Otter on floats, he said.

The cause of the crash was not yet known. "Way too early for any speculation," Johnson said.

Johnson said the plane came to rest in some trees. Two NTSB investigators were heading to Iliamna on Tuesday, he said.

In late June, another DHC-3 Otter crashed in a mountainous area in southeast Alaska, killing all nine people on board.

The sightseeing plane crashed on a steep cliff about 25 miles from Ketchikan, killing the pilot and eight cruise ship passengers. The excursion was sold through the cruise company Holland America and operated by Ketchikan-based Promech Air.

Another Otter was involved in an August 2010 crash in Alaska that killed former U.S. Sen. Ted Stevens and four others.