Here we are, yet again.

Another morning became another nightmare in the subway, this time injuring nearly three dozen commuters. And thousands of others dealt with a day of cascading delays, and an alphabet soup of service changes and suspensions that lasted into Tuesday evening’s rush.

Yet, still, there’s no sense of urgency from those in charge. Neither Gov. Andrew Cuomo nor Mayor Bill de Blasio went to the scene. Cuomo controls the subways. Thirty-four people in de Blasio’s city were hurt, thousands more were affected. A statement from de Blasio’s spokesman said he would “monitor the situation.” In a statement, Cuomo called the incident “an unacceptable manifestation of the system’s current state.” Neither did or said enough.

Two cars of an A train derailed and slammed into a subway wall near 125th Street after the emergency brakes were automatically activated Tuesday morning, according to new MTA Chairman Joseph Lhota. While the injuries were minor, there was plenty of panic as commuters tried to evacuate by walking along the tracks. Delays and service problems quickly spread through the system.

The activation of an emergency brake might have no connection to the decades of neglect of the subways. But it doesn’t matter. The incident again highlights how one trouble spot can cascade through and cripple the system, and how desperately attention, maintenance and upgrades are needed.

The derailment reminds us again of the need for quick and accurate information. Signs on subway cars tell riders not to evacuate unless they’re directed to do so. But in a moment of panic, with no announcements and no information, it’s not surprising that Tuesday’s commuters tried to find a way out. The MTA has to reevaluate its protocol and improve its emergency communications with riders.

In the end, passengers helped one another, again showing the resilience of New Yorkers in a crisis.

Lhota was quickly at the scene, reflective vest and game face projecting control. Just days into his new stint, it’s already clear just how much work he has to do.