At least 4 die after 2 small planes collide over Alaska, authorities say

It was not immediately clear what caused the two small propeller planes — which had pontoons to land on water — to crash near George Inlet about 1 p.m., Alaska Standard Time.

Lt. Brian Dykens, a Coast Guard spokesman, said that passengers of Princess Cruises were on the planes, but that he did not have further details.

More than 50 members of the U.S. Coast Guard were using helicopters and boats to search the waters for the missing people, Dykens said.

He did not have information on the conditions of the 10 people who were injured, but he said they were rescued and taken to a hospital.

One of the planes, a de Havilland DHC-2 Beaver, was carrying five people; the other plane, a de Havilland DHC-3 Otter, was carrying 11 people, Dykens said.

Princess Cruises did not immediately respond to a request for comment.

The Federal Aviation Administration and the National Transportation Safety Board are investigating the crash.

This article originally appeared in The New York Times.