Neighbors said the dead included an 8-year-old boy and his grandfather, but officials would not confirm that. Emergency officials did confirm that the three dead were found in two units, one above the other, in one of the apartment buildings.

The blaze, in the 400 block of SW 155th Street, left dozens homeless as well, said Red Cross officials who were trying to find shelter for the displaced families.

Sgt. John Urquhart of the King County Sheriff's Office said the fire is considered "suspicious" because investigators can find no way that the blaze could have started accidentally. He said investigators have determined that the fire started on the outside of the easternmost building.

The blaze was reported at about 12:45 a.m. - an hour when many residents had been fast asleep.

"I heard an explosion and glass shattering," said Lisa Johnson, a resident of the apartment building. "So I automatically had my granddaughter with me and came out."

Flames rage through the Burien apartment complex.

The first fire crews roared in, sirens wailing and horns blaring, to find a two-story apartment building with heavy fire and smoke pouring from the front of the building, said Dave Nelson, spokesman for King County Fire District 20.

The two-alarm blaze quickly escalated to a three-alarm fire when an adjacent apartment building's roof caught fire, and more fire crews were needed to battle the spreading flames.

Kenneth Mason, who lives nearby, came running when he saw the crackling flames and that's when he spotted five people, including a baby, trapped behind a jammed-shut glass door in the burning building.

Mason yelled at a woman in the trapped group.

"I said, 'Get out! Get out! There's a fire! There's a fire!' and she said, 'We can't get out!' And my friend Sam grabbed a big old brick and went and busted the glass door," he said.

"And they threw the baby out and gave me the baby, and the rest of the guys came out - and then the fire really got bad."

Amid the mayhem, a teenage girl jumped from a second-story window in another part of the building, suffering injuries.

Charred walls are all that remain of the apartment complex after the fire.

The first building was completely destroyed and the second building suffered major damage.

Six people were treated at area hospitals, including the girl who jumped from her window. Other injuries include burns and smoke inhalation.

As of Sunday morning, fire officials were still accounting for occupants of both buildings. Many people went with family and friends and to Highline Medical Center to be with family members who were injured.

No firefighters were injured battling the fire.

Firefighters from around South King County assisted in fighting the fire including Renton, Tukwila, Kent, Seatac, South King Fire and Rescue, North Highline, King County Medic One, King County Fire District 20, Seattle and King County Sheriff Fire Marshals Office.

The Seattle Chapter of the American Red Cross is assisting nearly 20 displaced people and sheltering them at a local church. About 30 to 50 people were living in the apartments.

Agents with the U.S. Bureau of Alcohol, Tobacco, Firearms and Explosives were at the scene Sunday morning, assisting with the investigation.

At this time due to the building's weakness fire investigators will have to wait until its safe to go inside the first building to determine the cause.

Damage estimates are not available at this time.

Anyone who wishes to share their photos or video of the fire may send them to tips@komo4news.com.