A small plane carrying four people crashed into shallow waters next to a remote coastal town in Alaska on Wednesday, killing everyone on board, according to officials.

The Piper PA-24 was en route to the Seldovia airport after taking off from Anchorage, a statement from the Alaska Department of Public Safety indicated. Seldovia's airport is located approximately 136 miles southwest of Anchorage.

Following the crash, the aircraft became submerged in about 15 feet of water in the Seldovia Slough, near the shore, said Clint Johnson, the National Transportation Safety Board’s Alaska region chief. Authorities reported that troopers had to wait for the tide to recede before they could access the wreckage.

Troopers successfully recovered the bodies of the four adults from the plane. These individuals are being sent to the medical examiner’s office, and their identities will not be released until their next of kin have been notified, according to the Department of Public Safety.

The cause of the crash was not immediately clear. The NTSB is currently investigating the incident.

U.S. Sen. Dan Sullivan, of Alaska, stated he would receive a briefing from the NTSB and the Federal Aviation Administration as their investigation into the cause proceeds. "These tragedies are heartbreaking and unacceptable, which is why aviation safety and infrastructure in Alaska continue to be a top focus of mine," Sullivan said in a Facebook post.

This incident occurred less than a week after another plane crash in western Alaska, which resulted in the deaths of all eight people on board. In that prior event, the aircraft was reportedly making its second runway approach in heavy fog, and its pilots were unable to see the gravel airstrip, authorities said.