ABC World News Tonight on Instagram: "A catastrophic explosion rocked a neighborhood in Hayward, California, destroying at least two homes. Dozens of firetrucks rushed to the scene as first responders combed through the smoldering debris in search of possible victims. At least six people were injured, three seriously, officials said. Authorities say prior to the blast, a construction crew hit an underground gas line Thursday morning. Complete coverage this evening on #WorldNewsTonight."