Firefighters are trying to determine what caused a three-alarm fire at a French Quarter hotel around midnight.

According to the New Orleans Fire Department, the fire started around 11:58 a.m. at The Oliver House Hotel at 822 Toulouse St. Firefighters arriving at the scene found a heavy fire in the rear of the three-story masonry constructed building.

First responders battled the flames for 30 minutes before calling for a third alarm at 12:39 a.m. NOFD said that the location of the fire and proximity to other buildings called for additional personnel at the scene.

“The age and stability of buildings in the French Quarter will always be a concern, as well as the number of people this hotel services,” a statement from NOFD said.

No injuries to hotel guests, employees or firefighters were reported. The fire was brought under control at 2:14 a.m.