LAKE FOREST, Ill. (AP) _ The mysterious death of a 9-year-old boy has been blamed on a hinged ledge covering a storage compartment in his family's van, police say.

The victim, Robert Pekarek, may have been unconscious for as long as 10 minutes, unable to lift the fallen ledge off his neck, Lake Forest Police Cmdr. Ted Hironimus said Friday.

The ledge and the storage compartment rim were upholstered, police said, and that may account for the fact that no marks were seen on Robert's neck when his body was found in the van last Saturday.

Hironimus said the boy had apparently been reaching into the storage compartment to retrieve some football cards when the accident occurred.

''It apparently happened so fast that the boy was in no position to do anything to get help,'' the commander said.

The van was parked in the Pekarek family's driveway at the time of the accident, and the boy's mother was in the front yard with her other children.