Hub residents from Kumamoto, Japan, were left fearing the worst for loved ones back home after a massive 7.3-magnitude earthquake sent shockwaves through the island nation, leaving at least 19 people dead and hundreds of people trapped under collapsed buildings and debris, officials say.“I’m very frustrated, I can’t do anything for my friends, my family,” a shaken Mika Stoltzman told the Herald through tears last night as she and two other Kumamoto natives met at the Gyu-Kaku Japanese restaurant in Cambridge after struggling to reach loved ones back home.