A day-care provider had six children in her van strapped into child safety seats that were either improperly attached or in such disrepair that the seats were unusable. One pair of nervous new parents stopped in on their way home from the hospital and found they hadn't locked into place the child safety seat carrying their 2-day-old baby.

So it went Thursday afternoon at the child safety seat checkpoint at the Prince Frederick Volunteer Fire Department, where Maryland State Police officers, area sheriff's deputies, county health workers and child safety advocates inspected the child safety seats in the cars of more than 60 Southern Maryland residents. State law requires all Maryland residents traveling with children under 4 years old or under 40 pounds to use a child safety seat.

Safety advocates used Thursday's checkpoint to put into service a new mobile child safety checkpoint trailer, which will be overseen by the Charles County Sheriff's Office and used throughout Southern Maryland at checkpoints held monthly by local law enforcement agencies. The trailer was the second of four planned mobile safety facilities to be put into service around the state by the Maryland Safe Kids Coalition, a nonprofit organization focusing on preventing childhood injuries.

Charles County Sheriff's Capt. Joseph C. Montminy said he was not surprised that the volunteer child safety seat inspectors found so many violations Thursday afternoon.

"Most people don't know how to put these child seats in properly," Montminy said. "This is not something that is worth taking a chance over."

Day-care provider Patricia Mutchler, of Our Little Day Care in Sunderland, said she got a wake-up call when she pulled up with her van full of six children, ages 11 months to 4 years. Inspectors found that four of her six child safety seats were unusable and had to be thrown away, and the other two were not properly secured.

"I found out I don't have a safe van," Mutchler said as inspectors weighed each child and outfitted the van with new safety seats, provided after a cash donation to the Safe Kids Coalition. Mutchler, who was not ticketed for the safety seat violations, said she will have her van's safety seats checked more regularly.

Barbara W. Beckett, chairwoman of Safe Kids, said that there is much that most parents don't know about child safety seats, including that the seats must be discarded after they are involved in a car crash. A 1998 study of Maryland drivers conducted by Safe Kids found that more than 87 percent of child safety seats were installed or used incorrectly.

Mark and Tracy Williams, both 31 and of Lusby, were so worried about installing their child safety seat correctly that they stopped by the checkpoint on their way home from Calvert Memorial Hospital, where their daughter, Sara Michelle, was born on Tuesday. Tracy Williams still had her hospital identification tags on her wrist.

They quickly discovered that despite the care they had taken to follow the instructions with their new safety seat, they had not locked the seat into place before leaving the hospital.

"A lot of seats out today are so technical you almost need help putting them in," said Tracy Williams, an elementary school teacher.

"It's our baby. We want to make sure everything's done perfect," said her husband.

CAPTION: Rebecca Martin, center, and Mariterese Briscoe of the Calvert County Traffic Safety Council check to see whether the car seat they are inspecting is on a recall list. Inspectors checked child safety seats in the cars of more than 60 Southern Maryland residents.

CAPTION: Debbie Jennings, coordinator for the Calvert County Traffic Safety Council, inspects the child safety seats installed in Pat Mutchler's van. The seats then were removed for a closer look.

CAPTION: Inspectors check the weight of Matthew Scott, 2, to make sure his child safety seat is adequate for his size.