Former Bethel Mayor Eric Middlebrook, 68, and three family members died Wednesday afternoon when the small plane he was piloting crashed in the Seldovia Slough, approximately 136 miles southwest of Anchorage, Alaska.

The victims were identified as Middlebrook, Daniel Simons, 82, of Los Gatos, California; Ronald Schmidt, 65, of San Jose, California; and Lance Schmidt, 20, also of San Jose. Public records indicate the four deceased were related.

The single-engine Piper PA-24 departed Merrill Field Airport in Anchorage en route to the small town of Seldovia when it crashed around 1:15 p.m. local time. The aircraft submerged in about 15 feet of water in the semi-frozen slough, complicating rescue efforts.

Alaska State Troopers recovered the bodies from the submerged aircraft after the tide receded around 6:30 p.m. The National Transportation Safety Board (NTSB) has launched an investigation into the cause of the crash, and the state medical examiner's office is conducting autopsies.

Middlebrook, who served as mayor of Bethel, a western Alaska town, from 2006 to 2011, was remembered as a seasoned pilot with a "quiet and gentle" demeanor. He owned a commercial refrigerator business and frequently flew throughout Alaska to service equipment in village stores, according to Mark Springer, a member of the Bethel City Council. Springer described Middlebrook as a "fixture in the community" and a "respected guy" well-known across the Yukon-Kuskokwim Delta.

Ronald Schmidt, identified as Middlebrook's brother, had previously described him as "very talented and very smart" in a 2006 interview with the Appeal Democrat newspaper when Middlebrook was elected mayor.

U.S. Senator Dan Sullivan of Alaska stated on Thursday that he was "praying for the families and love ones of those who were killed." He added that "aviation safety and infrastructure in Alaska continue to be a top focus" and that he would receive a briefing from the NTSB and the Federal Aviation Administration (FAA) as they investigate the incident.

The crash occurred less than a week after another plane went down at a remote military site in western Alaska, resulting in the deaths of all eight people on board. That incident involved a plane making a second attempt to land in heavy fog.

The Piper PA-24 is a single-engine, low-wing aircraft with a capacity for one pilot and up to five passengers. Middlebrook was piloting the aircraft at the time of the crash. He is survived by his wife, Molly.