PORTLAND – A Kennebunkport man admitted in U.S. District Court on Friday that he set a $1 million fire at an Arundel boatyard last summer.

Christopher Conley, 19, pleaded guilty to arson of a building used in interstate and foreign commerce and aiding and abetting such conduct. He faces between five and 20 years in prison.

Conley and a juvenile broke into Southern Maine Marine Services during the early morning of July 7, according to court records.

During the burglary, the two noticed surveillance cameras but could not find a video recorder.

They decided to burn the buildings in order to destroy potential evidence.

They spread gasoline in the area and placed propane tanks at various locations and opened the valves, court documents said.

No injuries were reported in the fire, which was discovered after the alarm sounded at about 4 a.m.

The blaze damaged a wooden building and destroyed a metal building and its contents.