Metro officials said yesterday that they will study possible measures to improve the safety of the transit system's escalators after this weekend's unusual accident in which a Northwest Washington girl was killed after her parka got caught in an escalator at one of the subway stations.

"This is such a freak accident," said Theodore Weigle Jr., deputy general manager for Metro. "When you consider the hundreds of thousands of people who use the escalators every day without an incident -- we'll have to be very deliberate and cautious about what we do to further improve their safety."

The girl, identified by D.C. police as Melissa Gilbert, is the daughter of Denise Wright and Claude Gilbert of 723 Madison St. NW. She was with her grandmother and identical twin sister Melanie when she apparently fell and the accident occurred, authorities said.

The grandmother, Elizabeth Truesdale of 3746 Hayes St. NE, was taking the children downtown Saturday to buy them roller skates, one day before their third birthday, they said.

The trio was riding the escalator down to the Minnesota Avenue Metro Station when the nylon strings of Melissa's parka snagged in the treads at the bottom of the escalator, Metro police said.

Weigle said yesterday that a station official turned off the escalator with a key as soon as he heard screaming. "It was probably a matter of seconds, or a minute," he said, but the girl had become so tightly pinned to the steps that it took 20 minutes to free her.

D.C. firefighters called to the scene could not detect any pulse in the girl. She was taken to D.C. General Hospital where she died about 6:05 p.m. The D.C. Medical Examiner's office said yesterday that the cause of death was asphyxiation.

Truesdale was in seclusion yesterday with friends and family. "If I could die, I would die," she said.

All Metro escalators were installed and are maintained by the Westinghouse Elevator Co. Ronald Boice, the regional director, said he has not heard of another escalator fatality in his 20 years with the firm.

Metro officials said the escalators can be stopped in a variety of ways -- either by the attendant in the booth, by using a key, by delivering a hard kick to the metal sidewalls at the top or bottom landings, or by pushing an emergency button at the base of the escalators.

None of the methods is advertised for use by the public, however, because of the possibility that a sudden stop would pitch a load of passengers forward, causing injury, according to Marilyn Dicus, a Metro spokeswoman.

"We've had injuries," said David Cooksey, director of facilities and maintenance for Metro. "We have had people get articles of clothing stuck in escalators before. We've had sprains and strains. The most injuries, of course, are when the escalators rather inexplicably stop and people fall."

Weigle said Metro has, over the years, tried to make the escalators safer, especially for the elderly. Speeds have been slowed from the original 120 feet a minute to 90 feet a minute. "In Moscow, the subway escalator moves in excess of 200 feet a minute," he said. "In London, to the best of my recollection, it's 140 to 150."

Escalators at the newest stations have warning signs, as well as yellow signal tape and green warning lights at the tops and bottoms of the stairs. Overhead lights are being installed at some locations, Weigle said.

The Minnesota station, in far Northeast, was nearly deserted yesterday. The few riders there were not familiar with the emergency buttons.

One of them, Cheryl Harrod, 32, said she always holds her daughter's hand on the escalator but still worries. "I never knew about the button," she said, "and there it is -- right there.