Shut the main before you call, if the ceiling is moving.

1. Find the meter. In most of these houses it is inside, on the wall that faces the street, down low.
2. The house valve is on the house side of the meter. Turn it clockwise until it stops.
3. Open a faucet on the lowest floor and one upstairs so the lines drain instead of sitting full.
4. If that valve is weeping, or it will not move, leave it. Forcing a seized valve is how a basement fills. Call from there.

Apartments in a triple-decker sometimes share a main in the cellar and have a second valve for the floor. Shut the floor valve if you know which it is. If you do not, shut the cellar main and tell Tom which floor you live on.

The city shutoff at the sidewalk is not yours to turn. If the house valve has failed, he brings the key and talks to the water department. Write down what you already tried.