Shortly after 6 p.m., a cannon onboard Old Ironsides misfired and seemed to have lobbed a projectile at a building on the grounds of the Charlestown Navy Yard. Boston Police were requested to help find the projectile, in an unusual call that a BPD dispatcher had to relay to an officer twice, because the world's oldest commissioned warship is not in the habit of firing towards land and BPD isn't usually called on to help find errant projectiles.