Two small planes collided midair Sunday about 20 miles north of Anchorage, killing all five people aboard, officials said.

A man and his three children in a Cessna 170B and the pilot of a Cessna 172 were killed in the wreck just after noon, according to National Transportation Safety Board investigator Clint Johnson. Both were single-engine fixed wing aircraft manufactured in 1955, state troopers said.

The planes were flying at altitutes between 500 and 800 feet when they collided above the Palmer Hay Flats in a remote area about 10 miles south of Wasilla.

"It appears that the westbound aircraft apparently saw the other aircraft at the last moment, tried to avoid the collision, but unfortunately that didn't work," said Johnson, who did not identify which plane that was.

Don Grant, who lives near the crash site, said he was outside when he heard a thud. He looked up to see the planes come plummeting down.

"I only recall hearing one sound when they hit the ground, so I'm pretty sure they hit at the same time," he said.

Killed were David Beauregard, 45, of Wasilla, and his three children: Ryan, 16, Conner, 13, and Remi, 9, troopers spokesman Greg Wilkinson said. The second pilot, William Smoke, 55, of Chugiak, was also killed, he said.

Rescuers found the planes about 500 feet from each other. Getting to the crash required using all-terrain vehicles, said fire chief Jack Krill.

Johnson said arrangements were being made to retrieve the wreckage and continue an investigation into what caused the crash.