Tonga authorities canceled tsunami warnings on Tuesday after a powerful magnitude 7.6 earthquake occurred deep beneath the Pacific Ocean floor.The US Geological Survey reported the tremor hit at a depth of 148 miles, a distance that prevented the generation of destructive waves.Residents in the capital of Nuku'alofa initially fled to higher ground following sirens but returned home once the threat was officially lifted.No casualties or significant structural damage were reported across the islands despite the intensity of the seismic activity recorded.