Metro

Now it’s Second Avenue floodway

Maybe they should build a Second Avenue Ferry.

An MTA subcontractor working on the Second Avenue Subway caused a water main break yesterday, knocking out the flow to one building and flooding the basement of a hospital, the city and MTA officials said.

Construction firm Skanska was installing a “geotechnical monitoring instrument” and hit the 12-inch pipe at East 66th Street and Second Avenue, officials said.

Water flowed into the mechanical room of Memorial Sloan-Kettering Cancer Center. It was later cleared.

The break also cut off the water supply to one apartment building, which was restored later in the day, the MTA said.

Workers were using machinery to pump water from underneath the sidewalk yesterday afternoon.

Both Skanska and the Department of Environmental Protection will remove the old pipe, replace it and repair the sidewalk, the MTA said.

The break is not expected to further delay the problem-plagued project.