VIDEO: Huge waterfalls cascade from penthouse pool after strong quake hits Philippines

A strong earthquake in the Philippines killed at least three people and trapped several others in a building.

About 30 people are still unaccounted for.

Incredible video shows huge waterfalls cascading from a penthouse swimming pool at this high-rise in Manila.

The 6.1-magnitude quake swayed skyscrapers and caused frightened office workers to run into the streets.

An international airport terminal has also been closed because of damage to the check-in areas, ceilings and sections of the departure area.

The U.S. Geological Survey's preliminary estimate is that more than 49 million people were exposed to some shaking from the earthquake, with more than 14 million people likely to feel moderate shaking or more.

A magnitude 7.7 quake killed nearly 2,000 people in the northern Philippines in 1990.

The Associated Press contributed to this report.