New York utility Con Edison tonight began to pre-emptively shut off power in lower Manhattan and sections of Brooklyn to prevent damage to its network equipment if Hurricane Sandy floods underground conduits. "Lower Manhattan south of Wall St. has been shut down," the utility said on Twitter. "We are evaluating other areas as the storm progresses."

Several high-traffic web sites are reporting down time due to data center problems in New York facilities, including Gawker, Gizmodo, Mediaite and Buzzfeed. All those sites are hosted by Datagram, which operates a data center at 33 Whitehall Street, which is within the "Zone A" flood zone in lower Manhattan, which is under mandatory evacuation orders.

At least one other data center building in the flood zone, 75 Broad, is running on generator power.

The pre-emptive shutdowns could prompt more of the many data centers and telecom buildings to switch to generator power. Con Edison has notified Manhattan customers from 36th Street south that the company may have to shut off their electrical service if the underground electrical equipment becomes inundated with water, the company said. Similar warning have been issued to customers in flood-prone areas of Brooklyn, Queens, and the Bronx.

"Seawater can damage underground electrical equipment," Con Ed said. "Shutting the equipment down can help to limit the damage. That means the company would be able to restore service to customers faster."

Peer 1, a tenant at 75 Broad, reported that its facility switched to generator power at 5:40 p.m. Eastern time. Internap, which is also a tenant at the building, says it has reduced its staff presence at 75 Broad.

"Non essential personnel are working from home," said Bill Brown, VP, Data Center Operations at Internap. "Essential infrastructure operations personnel are onsite to ensure no impact to facility operations. They have designated 'safe' locations and are primarily responsible for emergency response and customer support throughout the storm."

Meanwhile, a number of web sites are reporting downtime due to data center problems in New York.

We'll be back soon! There was a data center battery failure after the power went down in Lower Manhattan. Generators powering up. #sandy — Gizmodo (@Gizmodo) October 29, 2012

Our site is down. Problems with NY-area servers due to Sandy. Be back ASAP. — BuzzFeed (@BuzzFeed) October 29, 2012

Gawker is temporarily down because the 57th Street Crane just flooded our servers with sea foam, or something. Back with you shortly. — Gawker (@Gawker) October 29, 2012

Mediaite is temporally down. Our NYC based Data center is down due to Hurricane Sandy. We will be back shortly. — Mediaite (@mediaite) October 29, 2012

Other major data hubs located south of 36th Street include 111 Eighth Avenue (the Google building), 60 Hudson Street, 32 Avenue of the Americas, and Intergate.Manhattan (375 Pearl Street).

Officials in New York are bracing for tonight's high tide, which is coinciding with the landfall of Sandy further south along the New Jersey shore. The National Hurricane Center projects the storm surge from the storm could exceed 11 feet in lower Manhattan, which could lead to flooding of manholes and even the subway system.

"Water levels at the Battery have been rising quickly and are now over 10 feet," Con Ed reported on Twitter.