A person of interest is in custody after a stabbing in the NYC subway Monday morning. It happened just after 6 a.m. aboard a southbound 1 train at the 145th Street station.

The heavy downpours wreaked havoc across the city with footage showing commuters overwhelmed by floodwaters in various subway stations.

NEW YORK CITY (WABC) -- Shocking video showed water rushing into the subway system in Manhattan during Monday night's downpours. Video captured by an eyewitness at 23rd Street and 28th Street on the number 1 train line showed the water even rushing into the subway car as riders stood on the seats to avoid the water.

There is a major subway shutdown on part of the No. 1 line in Upper Manhattan. Crews are still working to remove floodwater from the tracks at 168th Street in Washington Heights after a maintenance effort went wrong.

The biggest shock of the evening, though, was the scene at the 28th Street 1 station in Chelsea, where riders watched a brownish geyser erupt several feet in the air from a drain in front of the uptown platform’s turnstile.

WEST HARLEM, Manhattan (WABC) -- When there is baking, summer heat, New York City's 1 train is "number one," for all the wrong reasons. The train line has gotten the most complaints for being too hot - more than any other line in the city. If you think it's broiling topside, at least up there's a breeze, but underground, you're trapped in the heat.