The Sarawak Chamber in Malaysia is the largest cave in the world is 2300 feet (701 meters) long, 1300 feet (400 meters) wide, and more than 230 feet (70 meters) high.
In Indonesia, as elsewhere throughout the region, it was impossible to determine the exact toll, which will likely not be known for some time.
This earthquake unleashed a series of tsunamis Sunday that crashed into coastal towns, fishing villages and tourist resorts from Sri Lanka to India, Thailand and Malaysia, killing more than 13,000 people in at least nine countries and leaving thousands missing.
The 9.0 magnitude quake was the strongest in 40 years and the fourth- most-powerful since 1900, according to the U.S. Geological Survey.
The tsunamis also left thousands injured, thousands missing and hundreds of thousands homeless in Indonesia, India, Sri Lanka and Thailand.
It is the fourth-largest earthquake since such measurements began in 1899, according to the NEIC, tying with a 1952 quake in Kamchatka, Russia.
More than 4,500 people have been reported dead in Sri Lanka. Most of them, authorities said, were in the eastern district of Batticaloa. Thousands were missing and more than a half million displaced.
In southern Sri Lanka, 200 prisoners escaped when the waves swept away a high-security prison in Matara.
Witnesses in the eastern Sri Lankan port city Trincomalee reported 14 meter (40-foot) waves hitting inland as far as a kilometer (0.6 miles).
The Sri Lankan government declared a state of emergency, and, along with the government of the Maldives, has requested international assistance, the United Nations' Office for the Coordination of Humanitarian Affairs reported.
If you are looking for information on relatives or friends in the areas affected by the tsunami, here are some disaster hotlines from around the region:
To contact representatives from India
, call +91 11 2309 3054
To reach Thailand
, call their emergency hotline at +66 21672
For information about local residents in Sri Lanka
, call +94 11 536 1938, for tourists the number is +94 11 243 7061
In the Maldives
, the government hotline is +44 20 7224 2149
For more information on travelers in the Seychelles
, call +248 321 676