A Thanksgiving Day fire raced through a frame house in Seat Pleasant early yesterday morning, killing six children and injuring eight adults who jumped to safety from first- and second-floor bedroom windows. Two other children were saved by an uncle who pulled them through a window.

Three generations of a family lived in the house at 203 69th St., owned by James H. Williams, 52, and his wife Annie Mae, 47. The fire killed five of their grandchildren, including 7-month-old twins, Nathaniel Mark and Emanuel Mathew Williams, and the Williamses' 10-year-old son Joshua.

Seven adults, including a fireman, were treated for shock, smoke inhalation and minor injuries at Prince George's Hospital Center after the fire, described as one of the most deadly in the county.

Firefighters and relatives said the rapidly moving blaze and heavy smoke prevented the adults from finding and rescuing the children, who were sleeping in three of the second-floor bedrooms. Adults had been sleeping in two of the bedrooms occupied by the children.

A neighbor, Gloria Roots, said she heard an explosion next door about 8 a.m.

"I saw fire shooting out the window and people started jumping out the window," Roots said. "I saw one man jump out naked. Then another lady. They were screaming that their babies were up there. It's very tragic."

Marvin Williams, not a relative, was alone in a front bedroom on the second floor of the house when the fire broke out. He escaped by jumping through a window and landing in the front yard 20 feet below, injuring his right knee.

"I woke up choking and coughing," Williams said. "It had to have started downstairs. The smoke was the only thing that woke me up."

Investigators said the fire apparently started on the first floor of the Cape Cod house, but they had not pinpointed a cause last night. A Prince George's County fire spokesman said tests would be conducted on a kerosene heater found in the house and on a smoke detector to determine if it was working.

Feelings of futility and disbelief hovered over the working-class neighborhood just outside the District.

"I heard the mother {Annie Mae Williams} standing by the back porch yelling for her son, {Joshua, 10} to jump out the window. He was standing there but that window was already full of fire. There was nothing I could do," said Andre Butler, a next-door neighbor.

As firemen cut through the house's front porch roof with axes, dowsing the smoldering wood with water, Butler said: "It's not Thanksgiving after this. You can't sit down and enjoy anything."

The fire was first reported by a Prince George's County policeman on routine patrol who said he noticed smoke while driving on Central Avenue, about six blocks away. Cpl. Wayne McBride said he initially thought it was a pile of leaves burning "but decided to check it out anyway."

When he got to the house, McBride said that five or six adults already had gotten out and were lying in the yard, the driveway and in the back yard.

"Most were screaming about their kids inside. You could tell they were sleeping because they were not fully clothed," McBride said as he leaned against a neighbor's chain-link fence and stared at the charred house.

"The bottom floor was well off {in flames}. I went up four steps and it {the fire} was too thick," McBride said. "They were all on the second floor and there wasn't anything from inside. This is a terrible way to start Thanksgiving morning. A terrible way."

Besides James H. and Annie Mae Williams, neighbors said the house was occupied by their sons James Kelvin Williams, 21, and Joshua; daughters Saundra Gail, 25, and Tracy Williams-Ahmad, 24; Tracy's husband, Clifton Stephan Ahmad, 26; the Williamses' daughters' seven children, and Marvin Williams.

The dead were identified as Joshua; Tracy's three children, Clifton Stephan Ahmad Jr., 5, Justin Ahmad, 4, and Sheena Ahmad, 2; and Saundra's 7-month-old twins, Nathaniel Mark and Emanuel Mathew Williams.

A spokesman said firefighters arrived at the home two minutes after receiving an alarm. "There was no chance of rescue" because of the flames and smoke, said Lt. Col. Ward Caddington, the deputy fire chief for Prince George's County.

Fire department spokesman Tony Destefano said it was unclear whether two youngsters had moved to the vacant room during the night or if they had tried to escape there. Caddington said that all the children in the house were found in or near their beds.

James Kelvin Williams was sleeping in a back bedroom on the first floor with his nephews, James Q.R. (Crudifee) Williams, 4, and Samuel Williams, 2, Saundra's sons. He broke out a window and lowered the boys safely to the ground. The youngsters were not injured and were being cared for yesterday afternoon by a neighbor, Claradean McClaine.

Two of the Williamses' other adult children arrived at the scene and were overcome with emotion at the news that the children were dead.

Chiquita Williams was handed her nephew Samuel, who wrapped his arms tightly around her neck as she clutched him close to her, shook and wept.

A few feet away, Chiquita's brother Lloyd broke down and punched the side of a Red Cross truck with a half-balled fist, sobbing, "All my nieces and nephews . . . . All my nieces and nephews." Moments later, Lloyd Williams was handed Samuel's brother James, whom he held closely as he kissed the boy repeatedly.

The house was a home to the growing, close-knit family for nearly 20 years, but just last month Chiquita Williams moved out with her two children.

But some of the neighbors said that too many lived in the dwelling.

"That house was loaded down with people. So many people have been in that house for so many years and it has been reported so many times," said Roots, the next-door neighbor.

"The health department said there was nothing they cound do because it was all the same family."

Fire officials refused to comment on the possibility of crowding.

Five hours after the fire, Tracy Williams-Ahmad called neighbor Pauline Cole from the hospital to ask about her children. Cole, Tracy's friend of nine years, said she couldn't tell the distraught mother that her three children had perished in the fire.

"I just told her I didn't know where they were right now," Cole said.

The Williams family children were popular with neighbor children and were often at the center of community activities, friends said.

"The boys played with my daughter's boy and I'd take all of them out and play football and basketball with them," said neighbor Charles Holmes Jr. "In the summer we'd all go swimming."

The senior Williamses regularly attend services at nearby Faith Temple Free Will Baptist Church, according to the Rev. L.N. Forbes, who said that James Williams comes less frequently because of health problems. With a church deacon and an usher standing beside him, Forbes called the Williamses "regular, nice Christian people. I've never heard any other type of report on them."

Yesterday morning the church held a 6 o'clock sunrise service for Thanksgiving which attracted an overflow crowd that did not include the Williams family.

"I wish they would have come," Forbes said.

"Amen," said the deacon and usher in unison.

As the black morgue truck backed into the Williamses' driveway, Caddington acknowledged that the fire was among the worst in the county's history.

"This is as bad as I have ever seen in my 22 years with the department and the largest as far as loss of life in the last 10 years," the deputy fire chief said. "The very young and the very old are usually the victims because they are are not prepared to take care of themselves."

Seat Pleasant Council member Joan Perry called it one of the worst tragedies she had seen in 18 years. "I don't even feel like Thanksgiving."