The damage to the kitchen, exhaust ducts and neighboring businesses from a fire at the popular Cheesecake Factory Restaurant in Waikiki is estimated at $2.5 million, a Honolulu Fire Department spokesman said.

It’s unclear when the restaurant, one of the busiest in Waikiki, will reopen.

Forty firefighters from 8 companies responded to the 3:32 a.m. alarm at the Royal Hawaiian Shopping Center in the heart of the tourist district.

A cleaning crew was at work when the blaze broke out in the kitchen area, said Capt. Terry Seelig, Honolulu Fire Department spokesman.

The crew was evacuated and no one was injured. The 2-alarm fire was under control by 4:45 a.m. and extinguished by 5:30 a.m., Seelig said.

Kalakaua avenue was closed for 3 1/2 hours until fire trucks cleared the scene.

Seelig said the cause of the fire was a gas leak to the fryer in the kitchen that was ignited by the pilot light.

Arriving fire companies found heavy smoke in the kitchen and dining areas. The fire was confined to the kitchen, but it spread to the exhaust ducts, igniting grease in the ducts, Seelig said.

Smoke and flames could be seen coming from the roof of the restaurant fed by establishment’s ducts.