An elderly woman was killed and two small children were burned critically in separate house fires yesterday in Prince George's County.

Capt. Jim Mundy, a fire department spokesman, said Della Weakley, 68, an invalid who was home alone, died in a fire at 3810 33rd St., Mount Rainier.

Mundy said that when firefighters responded to the call at 8:10 a.m. they found flames shooting from the first floor bedroom window and onto the roof of the single-family house.

The blaze was extinguished within 30 minutes, Mundy said. He said the victim's body was found in a bed.

The cause of the fire, which caused an estimated $70,000 in damages, had not been determined last night.

In the other blaze, reported at 10:40 a.m. from 5305 Hamilton St., Bladensburg, firefighters arrived at a three-story garden apartment and found flames coming from the bedroom of the top-floor apartment, Mundy said.

Firefighters said a one-legged man was standing in the doorway of the apartment screaming. They found the man's grandchildren, 2-year-old Daniel Won and his 1-year-old cousin, Tae Won, on the bedroom floor. Neither had a pulse, Mundy said.

Firefighters carried the children from the apartment where the children were revived, and taken to Prince George's General Hospital. Later they were transferred to Children's Hospital, where they were in critical condition last night, according to Mundy.

The grandfather, who was baby-sitting the children, was identified as Bok-Suv, 60. He was taken to Leland Memorial Hospital, where he was in stable condition.

Mundy said Bok-Suv, who is Korean, did not speak English and did not know how to use the telephone. Neighbors who heard his screams called the fire department.