AUGUSTA — Federal investigators said a Maine Warden Service plane that made an emergency landing on Interstate 95 in Litchfield in April simply ran out of fuel.

No one was injured when the single propeller Cessna landed on the highway on April 26, prompting one driver to pull over to make way for the aircraft.

The Federal Aviation Administration determined that there were no mechanical issues with the plane, even though authorities had referred to an unspecified mechanical problem as a possible reason for the unexpected landing.

Flight experts said it is a pilot’s responsibility to make sure a plane has enough fuel.

The FAA’s report was released to the Kennebec Journal (http://bit.ly/195YXkK ) in response to public records request.

The pilot has since resigned and could not be reached for comment.