Wikipedia: 'New York Airways flew Vertol 107 helicopters from the rooftop helipad to Pan Am's terminal at John F. Kennedy International Airport from December 21, 1965, to February 18, 1968, when the service ceased due to inadequate passenger loads. For a short part of that time, they also offered service to Teterboro Airport.
Service to JFK resumed in early 1977 using Sikorsky S-61s. On May 16, 1977, about one minute after an S-61L landed and its 20 passengers disembarked, the right front landing gear collapsed, causing the aircraft to topple onto its side with the rotors still turning. One of the five 20-foot (6.1 m) blades broke off and flew into a crowd of passengers waiting to board. Three men were killed instantly and another died later in a hospital. The blade sailed over the side of the building and killed a female pedestrian on the corner of Madison Avenue and 43rd Street. Two other people were seriously injured. Helicopter service was quickly suspended, and never resumed'.
https://en.wikipedia.org/wiki/MetLife_Building#Helicopter_se...