The Transportation Safety Board says life vests and quick-release doors would not have saved the lives of four people on board a floatplane that went down near Tofino, B.C., because they were killed in the impact.

The Cessna 185 operated by Atleo River Air Services crashed during a six-minute trip to the community of Ahousat in May, killing the pilot and three passengers.

The crash renewed calls for quick-release doors and for all floatplane passengers to wear personal flotation devices.

But TSB investigator Bill Yearwood said the accident wasn't survivable because of the force with which the aircraft struck the water.

The board has not determined the cause of the crash, but Yearwood said all four victims died from the impact, not drowning. A final report on the crash will be released within a year, he said.

Katrina English, 22, her brother Edward Sam, 28, and their cousin Samantha Mattersdorfer, 24, all from the small coastal First Nations community of Ahousat on Flores Island, were killed in the crash, along with pilot Damon York, 33, of Tofino.

Last November, six people were killed after a crash off Saturna Island and a TSB investigation found four of them were able to get their seatbelts off as the plane sank, but couldn't get out the doors.