DUNKIRK, N.Y. -- The U.S. and Canadian Coast Guards have called off rescue efforts for three Pennsylvania residents who were aboard a plane that disappeared over Lake Erie Friday night.

Family members said Kevin Jesteadt, 24, wanted to ask his girlfriend, Lindsey Myers, 23, to marry him, and pilot James Regal, 22, of Butler, agreed to fly them over Niagara Falls for the proposal.

The plane took off from Zelienople, Butler County, and picked up Jesteadt and Myers at the Port Meadville Airport in Meadville, Pa.

The last known position of the plane was about 25 miles southwest of Buffalo, according to the U.S. Coast Guard.

Searchers have found plane parts, seats and cushions. New York State Police were still conducting sonar searches of the area Monday.