Joliet fire crews battled a fire at a Subway restaurant in Joliet Monday afternoon.

The Joliet Fire Department responded at 3:30 p.m. to the Subway at 1710 W. Jefferson St. for a report of fire after an off-duty fire officer in front of the business noticed smoke coming from the roof, the fire department said.

The officer went inside and alerted the workers that there was a fire in the roof, the fire department said. The employees and patrons of Subway were able to exit safely.

Company 6 arrived within two minutes of the call and found heavy pressurized smoke coming from the roof vents, the fire department said.

Crews were met with heavy fire and smoke as they accessed a narrow staircase to the loft of the building, the fire department said. The narrow stairwell to the space had detached from the wall, which made access from the inside impossible, the department said.

“Due to the dangerous conditions inside, crews went to a defensive attack to extinguish the fire,” including aerial operations, the fire department said.

Crews remained on the scene for two hours. There were no injuries, the fire department said.

Fire crews from stations 1, 5, 6, 8 and 9 responded to the scene. The cause of the fire is under investigation.