Kutenga, a female African elephant, was only 27 when she collapsed in her stall at the Philadelphia Zoo in 1991 and died despite heroic efforts to get her to her feet, including trying to lift her with the hook from a tow truck.

Peggy, 52, a female Asian elephant, fell to the concrete floor of the zoo's elephant quarters in 1994 and was euthanized shortly afterward because of debilitating arthritis and dental disease, which made eating difficult.

Monday morning, a keeper found Petal, 52, the oldest African elephant in an American zoo, lying on her side on the floor of her stall, where she died about three hours later.

The connection between the elephant deaths was made by the animal activist group In Defense of Animals, which maintained that there are "unanswered questions" about the latest elephant death and asked the U.S. Department of Agriculture to investigate.

A USDA spokeswoman said yesterday that there had been no formal investigation, but that the agency had "looked into the situation" and was satisfied that the zoo had done nothing to violate the Animal Welfare Act.

Steve Feldman of the American Zoo and Aquarium Association, which accredits zoos, called the IDA "a group that has an anti-zoo agenda. They basically run around the country using these ambulance-chasing tactics.

"This is an extremist group that neither has the expertise nor credibility to comment on these type of matters," he said.

"Animals are born and die every day," Feldman said, adding that "the Philadelphia Zoo is a great zoo."

Like Peggy, Kutenga had suffered from arthritis, in her left leg, after falling while trying to catch a peanut tossed by a visitor. A necropsy, or animal autopsy, has been performed on Petal, but zoo officials don't expect to know for several weeks what caused her death.

"The pathologists report that Petal appeared to be in very good condition, especially for an elephant her age," said zoo communications director Bill Larson. Petal came to the zoo in 1957.

An in-stall video monitoring system showed Petal collapsing at 4:19 a.m. Monday, Larson said.

One of her keepers arrived at 6:15 a.m. and alerted other staff, but Petal couldn't stand and died about 9:15 a.m.

IDA campaign director Catherine Doyle said that elephants often sleep lying down, but if they cannot right themselves they can suffer tissue death and crushing injuries to internal organs because of their massive weight.

Doyle questioned whether anyone monitored the stall video overnight. She asked, "What good is having a surveillance system" if it's not being watched?

Larson said that the video system is there to allow zoo staff to review overnight social interactions among the elephants "so that we're able to respond to any changes." Petal lived with two younger female African elephants who are to be transferred to a Pittsburgh Zoo breeding facility later in the year.

"It is not standard operating procedure here, or at most other zoos or animal-care facilities, to monitor elephants or other animals directly 24 hours a day, except in unusual circumstances," Larson said. *