An off-duty Walt Disney World employee apparently was startled Thursday by swarming wasps and fell 11 stories to his death at the Contemporary Resort Hotel.

The accident happened as Brian Hribek, 24, a host at the Disney hotel's Top Of The World restaurant, was showing his roommate the view from an observation deck on the 15th floor of the hotel, police said.

The roommate, Dwight Auber, 23, an employee at the Yacht and Beach Club Resort, told police that Hribek was sitting on the 4-foot-high concrete ledge at about 1 p.m. when the wasps suddenly appeared. He tried to brush them away and lost his balance, falling backward, Auber told police.

Hribek, who had come to the hotel to get his paycheck, fell to the fourth-floor deck just under the passageway of the monorail, which slices through the pyramid-shaped hotel. Disney officials closed the monorail for about three hours while authorities removed the body.

Auber, who shared an apartment with Hribek in south Orange County, could not be reached for comment.

"It was a tragic accident," said Orange County sheriff's spokesman Cpl. Doug Sarubbi.

The landmark hotel has two observation decks facing northwest with a view of the Magic Kingdom and Orlando. They are ringed by 4-foot-high concrete walls, but there are no railings or signs prohibiting guests from sitting on the ledge. One sign does tell guests to return indoors during a storm.

"There's never been a warning sign up there," said Disney spokesman Dave Herbst, adding there have been no other accidents on the decks.

He would not comment on whether the company would add any safety features to the decks.

A Disney employee who would not give his name said he was on the deck with a friend about 12:30 p.m. but left before the accident.

"We noticed the wasps," he said. "They were huge, all over the place. That's when we came back in. Then a little while later, someone came in screaming, 'Call 911!' "

Disney officials said they do not know where the wasps came from. A reporter who walked on the deck two hours after the accident found dozens still swarming.