Three people were killed and a dozen were injured in a five-alarm fire on multiple floors of the Marco Polo high-rise condominium on Kapiolani Boulevard this afternoon, fire officials said.

Police confirmed two of the victims were a woman and her adult son.

The deaths occurred on the 26th floor, where the fire started in a 36-story building with no sprinkler system, Fire Chief Manuel Neves said at an afternoon news conference at the scene.

About 12 residents and one firefighter were injured. Four of them, including the firefighter, were taken to a hospital in serious condition.

With the fire still smoldering, fire crews planned to go unit by unit, extinguishing blazing beds and couches and searching for survivors, Neves said. That could take anywhere from two to six hours, he added.

HFD spokesman Capt. David Jenkins said at least 100 fire personnel and more than 30 HFD units responded to the fire at the 2333 Kapiolani Boulevard building. The initial call at 2:17 p.m. reported a fire on the 26th floor, but the fire later spread to the 25th through 28th floors and involved multiple units.

Mayor Kirk Caldwell tweeted this evening that the fire was under control more than four hours after it began, at 6:32 p.m. But at 7:50 p.m. firefighters were responding to a “flare-up” in the building.

The Red Cross opened a shelter in the ‘Iolani School to house Marco Polo residents displaced by the fire.

Shayne Enright, spokeswoman for the city Emergency Medical Services, said several ambulances responded to a 2:30 p.m. call. Paramedics and emergency personnel evaluated and treated patients for smoke inhalation.

“Paramedics are expediting emergency treatment with a triage location inside the building,” she said. At 5:31 p.m., ambulance crews treated and transported their fourth patient, a male, in serious condition to a trauma center.

The building was partially evacuated but Jenkins said some residents were trapped in their units. Firefighters escorted some of the residents down the building’s stairways.

Neves said an evacuation team led by an assistant chief evacuated residents from the “hot zone” — directly above and to the side of the fire, which is at the Ewa end of the building. Smoke could be seen coming out of both sides of the high-rise and the Diamond Head side as well.

A Marco Polo resident who was outside the building told the Honolulu Star-Advertiser that he could see people in some of the windows of the building. A woman was seen yelling for help from the lanai of a unit just below some of the burned-out units.

Flames and heavy smoke were visible for miles away for hours. Glass from the windows and window frames rained down on the ground as the blaze raged inside. Heavy black smoke was visible from miles away.

The American Red Cross officials said its volunteers were helping residents of the building, delivering water to firefighters, and setting up the shelter for displaced residents to spend the night.

Coralie Matayoshi, head of the Red Cross in Hawaii, said a shelter at Seto Hall in ‘Iolani School opened at 7:45 p.m. “We don’t know how many people to expect …. At first we were thinking of Ala Wai Elementary, but we wanted somewhere with air conditioning.”

She said Seto Hall has room for about 175 people to stay the night. The Red Cross is providing cots, blankets and food. If more space is needed ‘Iolani School officials agreed to open up the gymnasium.

Marco Polo resident Navin Tagore said he was teaching an art class when friends began calling him up about a fire burning in the vicinity of his family’s condominium and he rushed home. “Yep, it was,” he said.

Some Marco Polo residents, after more than two hours of watching the fire continue to burn, raised questions why the fire department was taking so long to put out the blaze.

“With all of these fire trucks, I can’t understand why they can’t put it out,” said Marco Polo resident Barbara Hudman, who has lived at the condominium since 1979. “Something is screwed up.”

Troy Yasuda, who lives in a building across the street, was giving water to people who evacuated. “They were choking from the smoke,” he said, adding that people told him they evacuated through dark stairwells.

Police were yelling through megaphones for people still inside to come down, Yasuda said. He watched as people were carried out.

“It’s been an orderly evacuation,” said security guard Leonard Rosa, who was answering phones from the front lobby of the 31-story building near Waikiki. Police and firefighters were going door-to-door, he said.

Firefighters were checking on reports that there were people trapped in their units, Jenkins said.

Fourth-floor resident Aaron Dengler and his wife were helping their elderly neighbor get to an aid station the American Red Cross set up at a nearby park. “It doesn’t help to just stand and watch,” he said.

One resident who declined to give his name said he made it to safety after climbing the stairs from the 29th floor. The man said there was so much smoke, he could hardly see.

Both Caldwell and Neves said that if the building had had a sprinkler system — mandatory for high-rises built after 1974 — the fire would have been contained to the original unit and might be already extinguished.

The Marco Polo, a 36-story building next to the Ala Wai Canal and Ala Wai Community Park, was built in 1971 and has 568 residential units. It was built before the city began requiring sprinkler systems.

On Jan. 15, 2013, an early-morning, three-alarm fire at the same building caused $1.1 million in damage to two apartments, exterior walls and hallways but no injuries.

Residents of both units escaped, including an infant. Three floors of the building above the fire were evacuated as well as all the floors below.

The 2013 blaze started at 2:36 a.m. in a microwave oven in an eighth-floor apartment and quickly spread. The heat blew out the lanai windows of a corner unit on the eighth floor and reached the unit above.

Today’s fire is the worst high-rise blaze Hawaii has seen since a six-alarm inferno on April 1, 2000, that destroyed the top floor of the 16-story Interstate Building on King Street. No occupants were injured but a firefighter and fire captain were taken to the hospital suffering from smoke inhalation, and other firefighters were treated at the scene.

One third of Honolulu’s firefighters were called to battle that blaze, which started at 8:25 a.m. and was declared under control shortly before noon. More than 100 businesses were affected, most by water damage. The fire caused several million dollars in damages.

There are four to six hours left before fire crews let residents return to their units, Capt. Jenkins said just before 10 p.m. Meanwhile, people are allowed to go to their cars under escort.

Honolulu Star-Advertiser reporters Michael Tsai and Susan Essoyan and the Associated Press contributed to this report.