As early as the start of this week, one of New Jersey’s finest young athletes issued a P.S.A. regarding the health risks of skating cellar doors. It was the approach that caught Mr. Maserati off-guard on this particular door, but that’s not the only peril involved. Bobby Puleo — another New Jersey athlete who spent much of his career battling these slanted portals to the netherworld — once told skateboarding’s archive of record that, “A lot of people have this perception that those things are ‘easy’ to skate. You hit that lock or that handle, it could be Beth Israel time.”