A one-alarm fire caused extensive damage to a diet and weight-loss clinic near Clearview Mall in Metairie on Friday morning, officials said.

East Bank Consolidated Fire Department Director Joseph Greco said the cause of the blaze at MedLoss, 4501 N. Interstate 10 Service Road, remained under investigation.

Ched Lambert, of MedLoss, said he initially believed the building had been struck by lightning, but later it appeared to him the blaze may have been electrical in nature.

Heavy rains rolled through the New Orleans area Friday morning.

The fire was reported about 7 a.m., and 16 firefighters brought it under control in just over an hour, Greco said. Nonetheless, the building sustained a fair amount of damage, he said.

The clinic was closed at the time of the fire, and no injuries were reported.

Lambert said one of his employees was in the building at the time of the fire but didn’t realize anything was wrong because the flames were on the roof.

An off-duty fireman who was just leaving work saw the smoke from the blaze and banged on the door to alert the employee, Lambert said.

“The Fire Department was amazing and tried to take care of our building in the best way possible,” Lambert said. “They were impressive to watch.”

Lambert said MedLoss will set up a temporary office, possibly at Premier Fitness on Airline Drive in Metairie. “Hopefully, we can be back in our regular building soon,” he said.

Patients can call (855) MED-LOSS with questions, he said.