Four men, including two brothers from southern Ontario, were killed when a float plane crashed in southern Alaska, U.S. aviation officials said.

Greg Brophy, 44, and Sean Brophy, 49, from Oakville, Ont., were killed Sunday evening while returning from a day of fishing near Katmai National Park and Preserve, U.S. National Park Service spokesman John Quinley said in a statement.

The park is about 400 kilometres southwest of Anchorage.

The third victim was identified as their guide, Tom Beatty, 38, of Homer, Alaska. The name of the fourth victim, believed to be the pilot, has not been released.  

Greg Brophy was founder and chief executive officer of Securit, an international information security company headquartered in Oakville. In 1988, he founded Shred-it, the document destruction division of Securit.

He is survived by his wife, Tracey, and their three children, Christopher, Megan and Kirsten.

The National Transportation Safety Board is investigating the crash.