Maryland and Virginia authorities are trying to determine whether a 15-year-old worker fatally injured at a Clifton construction site last week slipped through a safety net of child labor and school attendance laws.

Officials of three state agencies in Virginia and the Montgomery County school system are investigating why James A. Ricketts was working on the roof of a house addition Tuesday instead of attending school.

Ricketts, who lived in Germantown and attended Martin Luther King Junior High School last year, was laying tar paper on the roof of a pool enclosure at a house in Clifton when he stepped through an open skylight and fell 30 feet onto the pool foundation, according to coworkers. He died Wednesday at Fairfax Hospital.

Since late August, Ricketts had been employed full time by Woodside Design and Construction as a carpenter's helper. His father Robert also works for the Silver Spring company.

The Virginia Department of Labor and Industry's occupational safety and health program and the Division of State Labor Law Administration are investigating whether the state's child labor law was violated, department spokeswoman Janice Hathcock said. The state Department of Commerce, which licensed Woodside to build in Virginia, also is investigating, officials said.

Virginia labor law prohibits persons under 18 from working "in any capacity in or about . . . roofing." It also prohibits youths under 16 from working "in any scaffolding work or construction trade."

"The construction occupation is a prohibited occupation" for 14- and 15-year-olds, Hathcock said. "It appears that the deceased was underage for that particular type of employment."

In addition, Montgomery County school officials are investigating whether Ricketts' parents or school employes failed to meet their responsibilities under Maryland's compulsory attendance law, school spokesman Bill Henry said.

Under that law, children ages 6 to 16 are required to attend school, with some exceptions, Henry said. Parents or guardians are required to see that their children comply with the law, which also calls on school principals to refer truancy problems to officials responsible for finding solutions.

Montgomery County school officials had assigned Ricketts to a special program this year, but he did not enroll, said a school official who asked not to be identified.

"Here's a 15-year-old who apparently lived in Montgomery County and has not attended school, which would be a violation of the mandatory attendance rule," Henry said. If the school system found cause, it could take the parents to court on misdemeanor charges, he added.

Officials at Woodside Design and Construction said they hired Ricketts on the recommendation of his father Robert, a carpenter who joined the company in July. Robert Ricketts told them his son was in his early twenties and planned to go to college, they said, acknowledging that they never verified the youth's age.

"We were under the impression that he was about 20. Had we known the facts, we would not have employed the son," said George Schneider, Woodside's secretary-treasurer.

Under a 1986 federal immigration law, new employes must fill out a form for their employer on which the date of birth is listed, but Schneider said the form "never made its way into our files."

Laura Ricketts, James Ricketts' mother, said in an interview last week that she completed the form for her son and listed his date of birth as Dec. 12, 1971. She said her family never misrepresented the boy's age to Woodside employes, but added that her husband might have spoken to them of another son's college plans, causing a misunderstanding.

Laura Ricketts said she does not fault the construction firm, and the family is not considering taking legal action.

"They can't bring my son back," she said.

Laura Ricketts said James had "dropped out" of school and planned to earn a high school equivalence diploma. "He wanted to be a carpenter like his dad. He wanted to do anything his dad did," she said.

Woodside employes interviewed at the Clifton construction site on Friday said they knew little about the youth. He worked hard and talked little, they said. He often worked with his father, who was on the job with him at 8000 Seven Hills Ct., where the accident occurred.

Woodside construction manager Gary Spencer said it had been raining Tuesday morning before James Ricketts went up on the roof to lay tar paper with another worker.

Ricketts rose to his feet, turned abruptly and stepped through the skylight, momentarily catching himself before falling onto the pool foundation, Spencer said.

"He was young and I would say he was inexperienced, as most young people are," one worker said. "Construction is dangerous. Experience is what keeps you from getting killed lots of times."