A building in New York’s Long Island that houses research and development facilities as well as a communications center for the Nassau County Office of Emergency Management lost utility power on Tuesday morning, after Hurricane Sandy caused failure of a nearby substation, and has since been operating on generator power.

Peter Curtis, a contractor who manages infrastructure at the Morrelly Homeland Security Center in the City of Bethpage on Long Island, said the substation went out around 4:30 am PDT on Tuesday.

“The facility lost utility power and we were on backup power at that point,” he said. The automated failover to generator power occurred smoothly, and the call center for communications between the county’s emergency personnel and its roughly 1.35m residents remained online without interruptions.

“We were able to ride through the outages,” Curtis said. He is president of Power Management Concepts, which oversees management of the critical infrastructure at the center.

Power outages in the Long Island Power Authority’s service territory affected more than 500,000 people since Sandy arrived in the US northeast on Monday evening, according to the authority’s website. There were about 6,500 active outages in the utility’s territory around 6pm EDT on Friday, including more than 1,000 customers without power in the Morrelly center’s neighborhood.

The utility said that as of 6pm, it had restored 37 of the 50 substations in its territory that had failed. Most customers, it said, would have power by the weekend of November 10 and 11, with remaining customers potentially having to wait for another week or longer.

In addition to the emergency-management office, the center houses a public-private research center that develops technologies for the homeland-security market. It was established as an economic-development initiative for Long Island.