Oahu’s only public shooting range is closed for the weekend because of an investigation into a brush fire allegedly started by an employee at the complex who fired a flare gun.

The closure is affecting hundreds of people who use the Koko Head Shooting Complex on Saturday and Sunday and postponed the Hawaii State Outdoor Pistol Championship, said Tony Alonzo, the range’s temporary assistant.

Alonzo said people usually begin showing up at the range at 4 a.m. and by 8 a.m. there is a wait list, even though the range doesn’t open until an hour later.

The city Department of Parks and Recreation closed the range because of the police investigation. On Friday, police arrested a 29-year-old Waialae Iki man who allegedly admitted to firing the flare that ignited the brush fire. He remained in custody Saturday awaiting charges of first-degree arson, a class A felony.

Russ Takata, president of the Chinese Gun Club of Hawaii, said he showed up at 6:30 a.m. Saturday and found the range closed. About eight to 12 shooters in the tournament were affected.

"I could smell the smoke, and there was yellow tape closing off the rifle and the pistol side," he said. "No big deal for us. We just have to find another weekend."

He said the shooting range has a waiting list 90 percent of the time it’s open on the weekend.

"I’m sure a lot of people came out there to find out it’s closed," he said.

After starting about 3:30 p.m. Friday, the fire spread quickly, aided by the dry conditions and wind, and burned about 20 acres, firefighters said. A police helicopter picked up six hikers trapped at the top of Koko Crater and lowered them to safety.

Firefighters returned Saturday morning to put out more hot spots, and a fire investigator recovered additional evidence and turned it over to police. Capt. Gary Lum, of the Honolulu Fire Department, said the fire department was still investigating.

Alonzo said he first noticed the fire about 20 minutes after the range closed on Friday. He saw smoke from the back of the rifle range and went to investigate. Two men, including the employee who allegedly fired the flare, were running toward the smoke, apparently to smother the flare, but they couldn’t climb over the steep dirt mound at the end of the shooting range. The fire quickly spread, and he told other employees to call 911.

Two employees behind the firing line told him some employees were "playing (with) a flare gun."

He later overheard an employee say someone dropped off an unwanted flare gun, and he heard the man accused of starting the fire tell police that he pulled the trigger.

"He’s one of my best employees," Alonzo said. "That hurt my feelings."

He said the man, a range assistant, has been working at the complex about seven to 10 years, and will be given administrative leave during the investigation. He added that the man is one of the best rifle shooters in the islands — a master-class shooter with the National Rifle Association and a distinguished shooter in the Civilian Marksmanship Program — and could lose his right to own a gun. State law bans anyone indicted for or convicted of a felony from possessing or using a gun.

"If this guy is going to be charged, he’s going to lose everything," Alonzo said. "He’s going to be out of his job, get rid of all his guns, the whole nine yards. He can’t even get close over here."

The range is normally closed on Mondays and Tuesdays and will reopen, at the earliest, on Wednesday.

Hawaii News Now video: Suspect arrested for arson after firing flare gun into dry brush, igniting fire