A deer that jumped a wall at the National Zoo was fatally injured by two lions Sunday as dozens of startled spectators looked on.

Zoo spokeswoman Pamela Baker-Masson described the incident as highly unusual. It began about 2:50 p.m. as visitors lined the perimeter wall of an enclosure that contained two female lions, and it involved a deer that may have entered from Rock Creek Park.

"Everyone was cheering, 'Go, go, go' " to encourage the deer to reach safety, witness Josh Shpayher said. "Everyone was rooting for the deer."

As recounted by witnesses, the deer, over as much as 20 minutes, was in and out of a moat while the lions clutched, clawed or swatted it. A crowd of spectators grew. Some shrieked, cried out or took children away.

The incident began, said witness Rob Ephraim, when the deer "ran between people" at the railing of the low wall around the sunken enclosure.

"It was running and it leaped," he said. After a hoof apparently clipped the railing, the deer plunged into the green, leaf-strewn water of the moat at the bottom of the wall. One lion went in after the deer and "jumped on it," Ephraim said.

The deer escaped, "then [got] caught again," Ephraim said.

As the episode neared its end, one lion dragged the deer to a stairwell area. The deer, a female, broke free and bounded toward the moat, the lion in pursuit.

Zoo personnel sent visitors away and got the lions indoors. With the enclosure empty, the deer left the moat on its own. It was anesthetized and taken for evaluation by specialists.

They found it "pretty evident" that the deer "would not survive," and it was euthanized, Baker-Masson said.

Shpayher said he arrived in the middle of the incident, as the crowd was swelling to at least 100 people.

When he asked what was happening, he said a woman told him that "a deer jumped in and the lions got him."

Video footage shows the deer seeming to wriggle from a lion's grasp and flee, with no obvious wounds.

But Baker-Masson said an examination indicated that besides head and neck scratches, the deer had a serious wound on its belly.

Many deer live in Rock Creek Park, where the zoo is located, and many have been spotted on the zoo grounds. But it is highly unusual for a deer to get into an enclosure, Baker-Masson said.