JEFFERSON, Wis. (AP) — Sheriff's officials have identified a man and a teenage boy killed when an ultralight plane crashed into a river in southern Wisconsin.

Jefferson County Sheriff Paul Milbrath said in a statement Wednesday that the pilot, 51-year-old David Plambeck of Edgerton, and his passenger, 16-year-old Max Burlingame of Fort Atkinson, died when the aircraft went down in the Rock River near Jefferson Tuesday night.

The ultralight had taken off from Fort Atkinson Airport just before it crashed about 8 p.m. The sheriff says the plane was nearly submerged when first responders arrived. Recreational boaters on the river helped emergency responders pull the two from the plane. They were pronounced dead by the Jefferson County medical examiner.

Federal aviation officials will investigate.