By late October , the testing for elevators and fire alarms at 72nd Street still had not been completed , and the MTA said that there was a possibility that the subway could open with trains temporarily bypassing 72nd Street . This had been done before in September 2016 , when subway trains in Chelsea temporarily bypassed several stations along 23rd Street due to bombings . There was a concern that 86th Street was also not completed , with three escalators not installed yet . The two stations were only conducting fourteen equipment tests a week , but there needed to be forty tests per week in order to ensure that the line would open on time . The tentative opening date was also clarified to " by December 31 , " with a possibility of a delayed opening . However , an engineer affiliated with the MTA stated that there was a possibility that the line could be delayed to 2017
bombings
2016 New York and New Jersey bombings
History of the Second Avenue Subway