PORT JEFFERSON STATION - Arson investigators are looking into what caused a large fire at the old Lawrence Aviation building in Port Jefferson yesterday afternoon.

Officials say the flames broke out in an abandoned building that sits on the property off of Sheep Pasture Road.

One firefighter was transported to a local hospital for observation.

The Long Island Rail Road (LIRR) service was suspended between Stony Brook and Port Jefferson because of the fire.

The Lawrence Aviation site, formerly a plant that produced titanium aircraft parts, has been designated a Superfund site by the Environmental Protection Agency (EPA). Fire officials say there is no connection between the cleanup site and the fire.