Updated

Army investigators believe the death of a 16-year-old civilian girl at a barracks on Fort Lewis was possibly drug-related, a spokesman said Wednesday.

Chris Grey, a spokesman at the Criminal Investigation Command headquarters at Fort Belvoir, Va., wouldn't specify what drug or drugs may have been involved. Toxicology results are not expected for at least a week, he said.

Grey said the dead girl and another 16-year-old civilian girl who was found passed out early Sunday were both acquainted with a soldier in the barracks.

The surviving girl was in stable and improving condition Wednesday at Madigan Army Medical Center, said Joseph J. Piek, a Fort Lewis spokesman.

"Once she is in a state that she can be interviewed by the Criminal Investigation Division, I'm sure the investigators will do so to gather the facts about what the girls were doing on post," Piek said.

The dead girl was identified by her family on her MySpace page as Leah King.

"Just so everyone knows, we have very few details about what happened to Leah," the family statement said. "But what we know, we are not supposed to share just yet."

Grey and Piek said investigators had not released information on how the girls entered the post and what happened before a 911 call.

Both girls are from the south Puget Sound area and neither was a military dependent.

Piek said part of the investigation will focus on policies for allowing civilian visitors on post and for guests at barracks. No overnight visitors are allowed in the barracks, and authorized visitors must leave the base by 2 a.m. on weekends.

Minors who aren't a member of their host's immediate family must be accompanied in the barracks by a parent or guardian.

Piek said a review has been started of a policy that allows anyone with a valid Department of Defense identification to escort a civilian — even an unrelated minor — onto the post.

"To what extent these policies were followed will be a subject of the ongoing investigation," Piek said.

The manager of a dry cleaning store near Fort Lewis told The Seattle Times she often sees teenage girls approach young soldiers at a parking lot across the street from her shop and ask for rides onto the post.

"It's easy for them to get on the post. It happens all the time," Plaza Cleaners manager Maria Dibbens said. "They want to get on base and see the young GIs."

Additional coverage from Q13 FOX Seattle.