A fire at a Staten Island dockyard sparked a massive explosion that left 16 people — including 13 firefighters and two emergency medics — hospitalized on Friday, according to the FDNY. The blaze ignited in the basement of a metal building at the rear of the coastal facility in Mariners Harbor around 3:30 p.m., fire officials said. Just over 50 minutes later — well after the inferno at the Richmond Terrace dockyard near Andros Ave. had risen to a two-alarm fire — the building was suddenly rocked by an explosion that fire officials described as “major.” One civilian and two...