BARRIE, ONT. -- Investigators returned to the scene of a fatal plane crash on Lake Simcoe in Ramara Tuesday to retrieve what was left of the ultralight aircraft.

The crash on Monday afternoon killed the pilot, who authorities said was the lone occupant.

"A substantial fire occurred after impact, and it appears the aircraft impacted the ground in a steep nose-down attitude," said Ken Webster with the Transportation Safety Board.

The ultralight hit the ice on Lake Simcoe about three kilometres from shore near Lagoon City.

Investigators said they would analyze the wreckage, witness accounts and the weather conditions at the time, along with the history of the 1995 ultralight, before determining what happened to cause the deadly crash.

Police said there were several people on the ice at the time and are hoping to speak with them.

"We are looking to speak with anybody that did see the crash or did see the plane just prior to the incident," said OPP Const. Ted Dongelmans.

Provincial police ask any witnesses to contact them at 1-888-310-1122.