Emergency crews are responding to a fireworks-related explosion that ripped through a single-family house near Mandarin Avenue and Sumatra Street in Hayward, California, on Thursday afternoon. Hayward police said the blast originated inside the residence, severely damaging the garage and sparking a fire. Officers have cordoned off the neighborhood east of Interstate 880 and urged the public to steer clear while firefighters secure the scene. Authorities had not reported any injuries or disclosed the cause of the detonation as of early Thursday evening, and an investigation is under way.