Flooding caused delays on multiple New York City subway lines Monday as torrential rain pummeled the Tri-State Area, where many were under flash flood warnings. MTA Chair and CEO Janno Lieber says riders can expect normal service for the morning commute Tuesday.

The subway system, which is more than a century old, is relied on by millions of passengers every day and weaves the city into a cohesive network.

The century-old system is being hit with more powerful and frequent storms, and it will take a multiagency effort to fix it.