An offshore magnitude 7.8 earthquake rocked the southern Philippines early Monday, damaging buildings and a key access bridge in a large southern city and setting off a 3-foot tsunami that washed ashore on nearby coasts. At least four people were killed and more than 200 others injured, officials said. By about five hours after the quake struck, the Pacific Tsunami Warning Center said the threat of a tsunami had largely passed. Waves of 3 feet were monitored in the Philippine provinces of Sultan Kudarat and Sarangani by land-based tsunami watch stations, Teresito Bacolcol, the director of the Philippine Institute of Volcanology and Seismology told the Associated Press