A fire in Pauoa destroyed the home of two adult brothers who inherited the house from their parents, neighbors say.

Heavy, dark smoke from the fire deep in the valley could be seen from miles away, including the H-1 freeway, as Honolulu firefighters Monday afternoon battled the three-alarm blaze on Pacific Heights Road.

“We heard the sirens going, and they just kept going, one after the other; they kept coming. There was so much smoke,” said Jen Wheeler, who lives two blocks away on Kaola Way.

The right front corner of the wooden house collapsed, as did the garage. Fifteen units responded with 59 personnel to the blaze at the 55-year-old, three-story, single-family home at 2453-C Pacific Heights Road.

Neighbors said two brothers in their 40s, Roy and Lee, were home at the time of the fire. They were standing on the street outside their home, and appeared uninjured, as they watched their family home go up in flames, they said. Property tax records show the home is owned by the trust of Spencer and Charleen Nishimura.

Honolulu Fire Department Capt. Scot Seguirant said one brother was working on the lower floor of the home when he heard popping noises and woke his brother, who was sleeping. The two managed to escape uninjured.

“I could see over that house flames shooting up into the sky and smoke just billowing,” said Richard Oliver, who lives on Booth Road. He said he attempted to shoot water onto the burning structure, but the heat was too much to bear. “The heat was so tremendous that even though I was standing 35, 40 feet from the house … it felt like 200 to 250 degrees.”

He said he yelled out to the owners to get away from the house. They told him the fire started from a generator and that there were propane tanks on the property, Oliver said.

“He has a lot of tools, so he runs a generator for a compressor, and I guess the heat got so bad that the rods caught on fire and it went from there,” he said. “There were a lot of other explosions, so I wasn’t too sure if I should go closer.”

Kimo Ford, who lives next door, called one of the brothers, who was crying when he answered the phone.

“I’m sorry for my neighbors,” said Ford, who has owned his home for 32 years. “At least I have a house to go to,” he said.

The fire remains under investigation, so no cause or damage estimate was available Monday.

The fire was reported at 1:56 p.m., and the first unit arrived at 2:02 p.m. It was brought under control at 4:15 p.m. and extinguished at 6:23 p.m.

The home is at the end of Pacific Heights Road, which was closed by police for hours.

Firefighters managed to overcome the initial low pressure from the water supply. Hawaiian Electric Co. was notified of a hazardous downed power line.

Another difficulty was that the garage, built level with the roadway on what one neighbor called wooden “stilts,” collapsed with a truck inside, leaving rubble, which made it difficult to fully extinguish the fire, Seguirant said.

Because the garage was above the house, built below grade, there was the threat of the truck and other debris sliding farther into the house, he said.

About a dozen people watched the flames from Booth Road.

“I was getting worried ’cause it was burning so hard it caught the main building over here,” said Warren Aki, a retired Honolulu firefighter who lives in the duplex next door. Aki and his wife were baby-sitting their 6-month-old granddaughter. “We saw … smoke first, then flames started popping. We kind of came out of the house because the smoke was too rough for her, and then we went into the cars.”

Embers were flying as firetrucks drove to the scene, Oliver said.

“There were embers flying, so I started shooting my neighbor’s house down ’cause he has a lot of foliage. I made sure I wet those things first, and then I shot down my roof and whatever else I could see that could catch fire from the embers,” he said, adding that he felt for the brothers, who didn’t know where they would stay that night.

“This day and age everything is so expensive, and a lot of people don’t have the means or extra cash, so I know this is gonna really hurt. Just by looking at his face and his demeanor, you know he’s really suffering.”