Twelve hours after her youngest son and daughter perished in a fire that engulfed their bedroom in a Suitland apartment, Kathy Blount sat in a large, blue chair in a sunny hospital nursery yesterday, keeping a quiet vigil over her sleeping 4-year-old daughter.

Blount said the little girl, whose head was wrapped with gauze to protect her singed ears, had sought to ease her grief by saying, "Don't cry . . . Junior and Pookie went up to visit the angels."

The children, 2-year-old Kathy (Pookie) Ingram and 1-year-old Samuel (Junior) Ingram, died after their father, neighbors and firefighters were unable to rescue them from the early morning blaze. Blount, 22, her boyfriend, Samuel Ingram, and the 4-year-old, Shontell Ingram, escaped with minor injuries. No one else in the four-unit brick building was hurt.

Last evening Prince George's fire officials said they had not concluded their investigation into the cause of the 2:30 a.m. fire in Blount's second-story apartment at 4692 Homer Ave. Blount said she had no idea how the fire had begun. She said there were no electric blankets or space heaters in the room where the children slept.

At Prince George's General Hospital, Blount appeared to be shrinking into an oversized sweatsuit as she described the harrowing events. She said that at about 1:30 a.m. she checked on the three children who were sleeping in the same bed, before going into the other room to go to bed herself. About an hour later, Blount recalled, Shontell came into the room saying, "Ma, fire!"

Blount ran to the bedroom door. "The only thing I could see was the bed on fire." She awakened Ingram, who grabbed Shontell and shoved her into the hallway as Blount ran downstairs for help. "Sam crawled in on his hands and knees," Blount said. "He grabbed for an arm or a leg, but he couldn't see or feel anything . . . the fire got too hot."

Derrick Johnson, the downstairs neighbor, said Ingram's pounding at the door awakened him. The two men ran back upstairs and tried to make their way into the apartment, but "the smoke would take all our breath," Johnson said. Another neighbor standing outside threw a rock through one of the apartment windows. Johnson recalled, "All you heard was a scream, then you didn't hear anything else."

Lucy Duff, who owns the 14-building Duff Manor complex near Suitland High School, stood outside the building yesterday while she waited for insurance agents and Red Cross representatives. Duff said she had heard about the fire on the morning news and had driven over. "This is the first fire tragedy we've had here," she said tearfully.

Blount, who works at the Prince George's Motor Hotel near the apartment, said she and Ingram, a construction worker, had no desire to return to the apartment. She said she plans to live with her mother in Landover for a while.

Blount smoothed the sheets over Shontell, turned to a visitor and said that she had pleaded with firefighters to save her children, but they could not get inside.

"I kept asking about my children . . . I don't know how they died . . . . How badly burned were they? The smoke just took them," she said weeping.