The New York City Fire Department has determined the cause of a two-alarm fire that broke out at the Appellate Division, First Department, courthouse at 27 Madison Ave. on June 30.

The roof fire was caused by an open flame of a torch being used by construction workers renovating the building, according to the FDNY. The flame came in contact with combustibles.

The fire was deemed accidental, the department said. There were no injuries. The second alarm was called in mainly due to the impact of heat and humidity on the firefighters.

The city's Department of Design and Construction's contractor was working in the area where the fire started, and temporarily sealed the roof June 30, according to Office of Court Administration spokesman Lucian Chalfen.

The Department of Citywide Administrative Services and their contractors addressed the major cleanup in the aftermath of the fire, Chalfen said. The building's electrical and elevator service were checked and were unaffected. All water resulting from FDNY activity has been removed, carpets shampooed and floors and ductwork cleaned, he said.

An environmental contractor provided equipment to clean the air by removing humidity and smoke odor, Chalfen said.

The court, on the corner of E. 25th Street, remained open and operational during the cleanup, he said.