A sinkhole opened Thursday morning in a children's playground at Fort Drum, dropping a woman about six feet below ground level.

"I just feel fortunate that it happened to me, an adult," Elene M. Nemergut said hours after her experience. "It scares me to think what would have happened if it had been a child."

Miss Nemergut, 35, Three Mile Bay, is a lead child and youth program assistant at the Child Youth Development Center on Chapel Drive, near the post's north gate off Route 11.

Shortly before 11 a.m., as her group of 3- to 5-year-old children were returning to the building, Miss Nemergut said she noticed a slight depression in the ground, "right in the middle of the playground."

The children had not been near it, however, she said.

Since it was something she had not seen before, she went over to it.

"I actually jumped on it a little bit, because I wanted to make sure it was not getting any bigger, and I wanted to show my co-workers."

The ground gave way, "and I fell straight down."

She was up to her knees in mulch, she said, and she estimated that the top of her head was about two inches below the level of the ground.

Her co-workers "prudently" kept their distance, fearing that more ground might give way, she said. Their phone call for help brought Fort Drum's fire department, public works personnel and safety officers. A call went out to the Watertown Fire Department for assistance, with Chief Daniel J. Gaumont leading a six-man rescue unit.

"My arms were free, so I wasn't really concerned until a fireman said they didn't know where this might go," she said.

An A-frame was set up over the hole, estimated at 3 to 4 feet wide, and a firefighter entered the hole and placed Miss Nemergut in a harness. She was successfully lifted out and was taken to Guthrie Ambulatory Care Clinic to be treated for shoulder and ankle pains.

A storm drain pipe was at the base of the hole, leading personnel to suspect that a rupture may have allowed water to escape and wash away some soil.

Although the child care center remains open, the playground is closed pending an investigation and corrective action by safety and public works personnel, a Fort Drum spokesman said.

Miss Nemergut, who expected to be back at work today, said the children "were concerned," but none became emotional during the episode.