Commuters on multiple New York City subway lines experienced significant delays during Tuesday’s morning rush hour, according to riders and the MTA.

The transit agency’s app showed disruptions on the B, M, F, 7, C, D, N, Q, R, E, 2, 6, J, 4 and 5 trains as of 9:15 a.m.

While a handful of service changes were previously planned for signal and track maintenance, most were unexpected and upended commutes.

The issues reported by riders and the MTA included switch and signal problems as well as trains’ brakes activating in transit.

The 7 train was seeing severe delays in both directions due to a person struck by a train at the Grand Central-42nd Street station, according to the agency.

The MTA said on its app that some trains whose brakes were activated had to be removed from service.

A spokesperson for the agency said many of the delays were resolving as crews worked through the various issues.

She pointed to the MTA’s website as the best place for riders to check up-to-date information on service changes.

Danny Pearlstein, policy and communications director for the nonprofit Riders Alliance, said the disruptions were “a powerful and frustrating reminder” of how much the subways need to be improved after decades of disinvestment and deferred maintenance.

“At the same time, today’s meltdown underground is yet another reason to make major improvements to our streets and deliver much better bus service that keeps riders moving when the subway can’t deliver the service we deserve,” he said in a statement.

This is a developing story and has been updated with additional information.