HARRISBURG, Pa., (CBS) – Pennsylvania Governor Tom Corbett Wednesday night signed a disaster emergency proclamation in response to this week’s devastating storm.

During a mid-evening briefing, Governor Corbett said 500 members of the National Guard were ready to respond, with nearly 300 already listed on active duty. The governor said he also declared a disaster emergency. At its peak, nearly 850,000 customers were without power.

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READ: Latest Power Outage Information

“The declaration allows us to tap into our emergency state funds and to assist with costs related to the availability of the guard … to opening shelters … and to providing generators where needed,” Corbett said.

PECO crews were swamped, trying to restore power to more than a half-million customers who were cut off by Wednesday morning’s ice storm (See Related Story). Because there were so many people without power over such a large area, PECO said it would be a multiple-day effort to get everyone restored. Officials said some people may not get their electric service back until the weekend.

In addition, several hospitals in the area lost their main electricity service and were running on backup power (See Related Story).

Villanova University and Rosemont College have closed for the rest of the week because of power outages and have asked students who could travel safely to return home.

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Travel was also a major problem throughout the state. Amtrak suspended its “Keystone” service between Philadelphia and Harrisburg Wednesday due to downed trees and wires along the tracks (See Previous Story). SEPTA experienced an abundance of delays and service suspensions that gradually improved throughout the day (See Previous Story). Philadelphia International Airport reported 139 cancelled flights.

Corbett also says the disaster emergency proclamation positions the state for federal assistance and that he’s asked President Obama to support an emergency declaration. The governor also warns that the proclamation means that the state’s anti-price gouging statute is in effect.

A state supported shelter was to be opened at 850 South New Street on the south campus of West Chester University.

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Corbett said 16 shelters have been established across the state.

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