A sprinkler on a lanai extinguished a small fire at a Kakaako high-rise today, Honolulu firefighters said.

Forty-seven firefighters responded to the two-alarm fire at 5:07 p.m. in building B of 801 South St. near the intersection of Kapiolani Boulevard and Alapai Street, said Honolulu Fire Department Capt. Scot Seguirant.

By the time firefighters got to the 28th floor unit about 10 minutes later, the fire already had been extinguished by the sprinkler system, Seguirant said.

“Bar none, sprinklers are the safest way to manage a fire,” he said. “It was there before firefighters were even able to get there.”

He said a properly designed building can minimize property loss.

The cause of the fire was undetermined, but damage was estimated at $2,500 for the structure and its contents.

A large group of firefighters responded to the alarm because a second-alarm was called when smoke was seen coming from the building. The second wave of firefighters were returned after they arrived at the building.

Authorities closed Kapiolani Boulevard between South and Cooke streets during the incident.