The New York Times explains how BTS and Jimmy Fallon's Tonight Show team were able to film in Grand Central Terminal in the middle of the night, and keep it quiet. The crew began setting up on Saturday night, Feb. 8, one of the quietest times of the week, around 10 p.m. After Grand Central Terminal was closed at 2 a.m., BTS' RM, Jin, SUGA, J-hope, Jimin, V and Jungkook began filming with two hours to nail the perfect video for "ON" from their new album Map of the Soul: 7 because the doors would open to the public again at 5:15 a.m. "The Tonight Show did not film inside Grand Central for free," reports The Times' Andrea Salcedo. "The Terminal charges a labor fee that includes staff used to supervise the production, electricians, on-site safety and customer service representatives, as well as a rental fee for the space." The subway scene was filmed two nights later inside a subway car that's no longer operational, but is regularly used for special events. “We were really excited about this one because we do believe that Jimmy Fallon and BTS bring diverse communities together and that’s exactly what New York City Transit does as well,” said Sarah Meyer of New York City Transit. “There is good synergy.” ALSO: Watch BTS discuss Friends and leads a cardio class on "Carpool Karaoke."