POLAND — A blaze razed one of the buildings at a shuttered private school for troubled teens that was once the center of abuse allegations and was mentioned in the murder trial of Kennedy cousin Michael Skakel.

The Elan School's buildings had been vacant since it closed in 2011. There was no electricity in the building that burned. It was fully engulfed by the time firefighters arrived Sunday morning, said Poland Fire Chief Thomas Printup.

The state fire marshal is investigating.

Testimony during Skakel's trial in 2002 indicated he confessed to classmates while at Elan, telling them he killed his neighbor Martha Moxley in Greenwich, Connecticut, in 1975. Skakel was convicted, but the conviction was later overturned.

The isolated therapeutic community was known for controversial practices, including harsh punishments for residents who failed work assignments overseen by peers and staff. In 2016, Maine State Police investigated the 1982 death of an Elan student who died after he was forced to fight in a boxing match with another student. No charges were filed.

The school was opened in 1970 by the late Joseph Ricci, a former heroin addict. He also owned the Scarborough Downs harness-racing track. He died in 2001.