An active shooter incident occurred in Midtown Manhattan, New York, officials said. Here's what to know about 345 Park Ave.

Officials said the gunman fatally shot himself after his attack, which set off a chaotic scene that rippled out into the heart of Manhattan during rush hour.

Jessica Chen said she and dozens of others barricaded themselves in a conference room on the second floor of 345 Park Ave. after hearing shots fired in the building.