From left, Hana Yoo, 14, who died in the fire, and Gong Joo, 14, Meena Yoo, 12, and Winnie Chung, 11, who were injured.
A sweet-natured Queens teenager who loved to play piano at her church was killed yesterday when her house was set on fire - allegedly by a roommate who was "high," police sources said.
Cops last night arrested a 27-year-old woman who they believe set the curtains afire around 3:30 a.m. because she thought someone was trying to break into the Bayside house on 215th Street.
A police source said it's believed the woman, Ok Ki Gang, was "high" but would not provide further details.
Hana Yoo, 14, who lived in the first two floors of the two-family house with her mom, sister and at least five others including the suspect, died after being trapped.
"This is so sad," sobbed one of her pals, Sarah Moon, 14.
"I used to visit her every day. She was shy, but she was fun and crazy once you got to know her.
"We used to watch Korean soap operas together.
"She loved to play the piano at church. She was very good and would often go to recitals."
Yoo, who was in the ninth grade at IS 25, regularly attended the New York Mission Church with her mother, Hee Ja Choy, and sister, Meena Yoo, a neighbor said.
Gabrielle Malkin, who lived upstairs, said she woke up her father when she smelled smoke drifting into their apartment.
"At first he said go back to sleep, but then we turned the light on and we saw all this smoke in the air - our eyes started burning," Malkin, 14, said.
After running outside, she saw two of the women who lived downstairs, screaming, "Help! Get help!"
Five women, including Yoo and Winnie Chung, 11, were taken to two hospitals in Queens and Jacobi Hospital, which has a burn center, in The Bronx.
One of the women remains in a critical condition, a Fire Department spokesman said.
At least two of the victims, Yoo's sister Meena, 12, and Gong Joo, 14, were later released.
A criminal investigation was quickly opened into the suspicious blaze when fire marshals found it had been set alight in three places, including a couch.
The woman arrested moved into the house about three weeks ago, sources said.
Apart from the woman arrested, neighbors said at least three mothers and four young girls had been living in the first two floors of the house.
They moved in about 18 months ago.
The house was not outfitted with smoke detectors, law-enforcement sources said.
Two of the mothers may have been away from home when the fire erupted.
"We used to often hear them singing music," one neighbor said. "But they were very quiet."
Additional reporting John Lehmann