UNITED NATIONS -- Tilly Smith, just 10 years old at the time, put her geography lessons to good use: by quickly recognizing the warning signs of a tsunami, the English schoolgirl saved about 100 people from near-certain death at a Thai resort. Tilly, now 11, visited the United Nations Thursday and met former president Bill Clinton, the U.N. envoy for the tsunami recovery. The Smith family all escaped the lethal waves after Tilly's early warning during their vacation on the island of Phuket.

Two weeks before the Dec. 26, 2004, disaster that took at least 178,000 lives, Tilly had studied tsunamis in her geography class in Oxshott, a community of about 5,000 just south of London. The children were shown a video from an earlier tsunami.

Tilly was armed with that knowledge when the Smith family decided to go for a morning walk on the idyllic beach near the JW Marriott Phuket Resort and Spa.

Suddenly, "I saw this bubbling on the water, right on the edge, and foam sizzling just like in a frying pan," she remembered. "The water was coming in, but it wasn't going out again. It was coming in, and then in, and then in, towards the hotel."

She recognized it as an indication that earthquake-driven waves were only minutes away.

Tilly turned to her mother, Penny, "and I said, 'Mum, I know there's something wrong, I know it's going to happen -- the tsunami."'

When her mother replied that it was just a day at the beach, "Tilly went hysterical," recalls her father, Colin, who decided to return to the hotel with her 8-year-old sister, Holly.

While Colin Smith relayed Tilly's warning to the hotel staff, the girl dashed back toward the beach filled with about 100 people. She told the Japanese-born hotel chef of the danger, "and he knew the word tsunami because it's Japanese. But he never saw one."

The chef and a nearby hotel security agent both spread the warning and the beach was swiftly evacuated -- minutes before the devastating waves struck.

The beach near the Marriott Hotel was one of the few in Phuket where no one was killed or seriously hurt.

On Thursday, she was welcomed at U.N. headquarters by officials of the International Strategy for Disaster Reduction, a Geneva-based U.N. agency that is trying to educate people worldwide on proper disaster response.

During last month's earthquake in India and Pakistan, scores of schools were destroyed and many children died under the rubble.

"Tilly's story is a simple reminder that education can make a difference between life and death," Clinton said before his meeting with Tilly. "All children should be taught disaster reduction so they know what to do when natural hazards strike."

Later Thursday, the former president sat next to Tilly on a couch at a midtown Manhattan hotel and asked her to tell him about what happened.

In countries such as Japan, Cuba, Iran and Bangladesh, people have learned to live with frequent natural hazards such as floods and earthquakes, said Salvano Briceno, who directs the Geneva-based U.N. disaster strategy agency.

"When you have only a few minutes, it is important to know the actions you must take to reduce your risk, such as running to higher ground to avoid the flood water," Briceno said.

Next week, Tilly will be back in school -- and in her favorite class.

"I like geography," she said.