The body of the third and final registered occupant of a small plane that crashed Sunday into a deep Mississippi River island quarry was recovered Thursday night and the investigation continues, the Washington County Sheriff's Office said.

Two of the three occupants have been identified, the Sheriff's Office said.

Larry Schlichting, 60, of Eagan, and Lucas Knight, 24, of North Mankato, Minn., were killed in the crash, according to the Ramsey County Medical Examiner's Office.

Authorities did not say whether one of the two identified men was piloting the plane.

Working in water up to 70 feet deep, searchers recovered the two bodies Tuesday afternoon from the privately owned quarry on Grey Cloud Island.

Search and recovery operations have been challenging, because the walls of the 200-foot deep quarry are sand-based, the Washington Sheriff's Office said previously.

As of Thursday, partial wreckage of the aircraft had been recovered, the news release said.

The single-engine Cessna aircraft left Fleming Field Municipal Airport in South St. Paul sometime after 2 p.m. Sunday and authorities were notified that it was missing Sunday night.

The first signs of wreckage were discovered just before midnight Sunday.

The Washington County Dive Team will continue to search for the plane's third occupant with help from the Cottage Grove Police Department; Hennepin, Carver, Ramsey and Dakota County sheriff's offices; and the Wisconsin and Minnesota Departments of Natural Resources.

Knight, who was originally from Coon Valley, Wis., graduated from Mankato State University in 2019. His social media profiles say he studied aviation.

Schlichting worked as a technical writer at MTS Systems Corp. in Eden Prairie and attended St. John's University in Collegeville, the University of Minnesota and Concordia University, St. Paul, according to his online obituary.

His Facebook page shows he enjoyed riding motorcycles and playing the guitar, as well as flying small planes. He is survived by a daughter, Alexandra, a son, Jeremy Schlichting, and his sister, Mary Bunting, according to the obituary.

Funeral services for Schlichting will be held at 3 p.m. Monday at White Funeral Home in Lakeville.