Hundreds of people evacuated the Ala Wai Plaza condominium complex Tuesday night after someone reportedly set fire to a two-story unit.

Police arrested a 28-year-old man on suspicion of first-degree arson.

The suspect reportedly resides at the apartment with roommates and allegedly started the fire, police said.

The fire was reported at 9 p.m. at Unit 1801 in the Park Tower of the 349-unit complex at 500 University Ave.

"The kids in the park were screaming," said resident Ashley Yonamine, 18. "They saved a lot of people’s lives."

Yonamine, who lives one floor below the fire, heard what sounded like a tea kettle whistling, but only after hearing the screams from Ala Wai Neighborhood Park realized it was the fire alarm.

Fire Capt. Terry Seelig said the cause of the fire remains under investigation, but it appears to have started on the lower floor. He said it caused extensive damage and had spread throughout the entire three-bedroom, two-story unit. Firefighters arrived at 9:04 p.m. and brought the blaze under control at 9:20 p.m.

No damage estimate was available Tuesday night.

Two other men who lived in the condo received help from the American Red Cross, but no one was injured .

Samuel Batista, 37, said his son, Luis Ortiz, shouted, "There’s a fire!" and Ortiz called 911.

He and his son went to the burning unit and began looking for a fire extinguisher and found the building’s house lines or hoses housed in cabinets in the hallway. He and his neighbor, Tom, and his son tried to tame the flames using two house lines and a fire extinguisher.

"If we didn’t do that, it would have burned at least three or four other units," he said. "We stopped it from escalating. It completely burned the one unit."

Fire Capt. Terry Seelig said when firefighters arrived they found the three battling the blaze.

Mike Aguirre, 47, said he was out walking the dog when "someone said fire! We walked out to the park and we could see the flames — good-sized flames coming out."

A group of teens playing basketball said they saw the fire and began taking video using their cell phones and iPods.

"We were playing ball, and we started hearing the fire alarm, and we were looking at the building and we saw the fire.

"We were yelling for people to come out," Welley said. "There’s fire! Get out!"

His cell phone video showed the bright flames shooting from the window, and a big fireball of something burning fall to the ground.

Mark Burke, 14, said, "I saw a lot of people looking down."

"I thought someone was dying in there," he said.

He said he first thought it was a car alarm.

"And I looked up and I saw fire," he said.