NEW : the Salvation Army iReporter says many homes destroyed in her Chile neighborhood . NEW : Witness to previous quakes said this one was strongest , most long-lasting . Mirko Vukasovic , a Santiago college student , was with host family in Santiago when quake hit .
NEW : CNN iReporter says many homes destroyed in her Santiago neighborhood . NEW : Witness to previous quakes said this one was strongest , most long-lasting . Luke Mescher , a U.S. college student , was with host family in Chile when quake hit .