Multiple police officers in New York City were seen responding Monday to reports of an active shooter in a midtown Manhattan building that houses the Blackstone investment firm and the headquarters for the NFL.Sources told Fox News that people inside the building on 52nd Street and Park Avenue were hiding on different floors, the kitchen and bathrooms.2 TEENS SHOT NEAR NYCS STONEWALL INN AFTER PRIDE MARCH: POLICENYPD and Sheriff's Department officers in protective gear were seen with guns drawn, Fox New York reported.Video taken by a FOX 5 NY employee showed several officers carrying a person, and other officers appeared to be tending to a person lying on the ground.The city's emergency notification system told followers to expect traffic and mass transit disruptions.FBI Deputy Director Dan Bongino said that FBI New York Field Office management personnel and agents were responding to provide support at the active crime scene.