The two earthquakes that shook the Indonesian island of Sumatra and caused tsunami waves to crash into the Samoan islands this week were unrelated, according to scientists at the University of Utah's Seismograph Stations. The events were separated by 16 hours and 6,000 miles. The epicenter of the Indonesian earthquake, measuring 7.9 on the Richter scale, occurred about 30 miles off the coast, near the city of Padang, a city of 900,000. A hospital was among the destroyed buildings in the city and the roof of the Padang airport also reportedly collapsed. The Samoan tsunami killed more than 100 when 20-foot waves smashed buildings and swept some people out to sea, and President Obama has declared American Samoa to be a federal disaster area.