A powerful magnitude 7.3 earthquake has struck just off the coast of Vanuatu, causing widespread destruction in the South Pacific island nation. The injured have begun arriving at a hospital and there are only unconfirmed reports of casualties. A tsunami warning was called off less than two hours after Tuesday's quake. With communications still down hours and official information scarce, witness accounts of casualties began to surface on social media and through patchy phone calls. It's not immediately clear how much damage was caused as phone lines and government websites remained down.