Reuters reports a powerful magnitude 7.7 earthquake struck the western Caribbean on Tuesday. The quake triggered evacuations as buildings shook across the Cayman Islands, in Jamaica, and in downtown Miami. However, there were no initial reports of significant damage. The epicenter of the quake was in the sea between Jamaica, the Cayman Islands and Cuba, at a shallow depth of 6.2 miles. The International Tsunami Information Center said an earlier threat of a tsunami wave had largely passed.