PORTLAND, Ore. – A two-alarm fire displaced families at a Northeast Portland apartment building early Wednesday morning.

The fire started about 5 a.m. at the building at Northeast Killingsworth and 27th Avenue.

Around noon, fire investigators took a suspect, 34-year-old Louis Duncan, into custody in connection with the fire. He lived in the apartment complex, police said.

Louis Duncan

Duncan was booked into the Multnomah County Jail on a charge of first-degree arson. He will be arraigned on Thursday at 1:30 p.m.

Investigators said Duncan is the resident that others suspected of starting the fire. Residents said he threatened to burn the place down as recently as yesterday.

The first fire crews on the scene early Wednesday said flames were roaring from the front of the two-story building.

Neighbor Kenneth Butler went around banging on doors in the six-unit building, alerting people to get out, residents said.

"He saved us all," said tenant Teresa White.

Nearly 20 people were displaced by the fire; half of them children. The Red Cross was helping them with temporary housing and food.

The cause of the fire remains under investigation.

Some residents expressed concern about erratic behavior by a man occupying the unit where the fire appeared to have started, saying he even threatened to burn the place down.

The streets around the fire were closed for several hours.