In the days since Superstorm Sandy pummeled much of the Northeast with severe winds and torrential flooding, donations to the American Red Cross have been pouring in.

The agency received nearly $35 million through early Friday morning, said Karen Stecher, a Red Cross spokesperson. "The public has been generous," she said.

The Red Cross has been operating shelters and offering food, water and relief supplies to areas struck hard by Sandy. On Thursday night, it housed almost 6,800 people in nearly 100 Red Cross shelters across 8 states. The agency has delivered more than 852,000 ready-to-eat meals and snacks so far, and served more than 215,000 meals.

Donations for Sandy have already exceeded the $8 million given over the entire recovery period for Hurricane Isaac, which struck the Gulf Coast earlier this year, according to Neal Litvack, chief development officer at the Red Cross.

While the initial outpouring has been strong, the destruction has been huge. Helping the millions left without power and thousands temporarily lacking homes or food is likely to cost the agency "tens of millions" of dollars, said Litvack.

Related: Sandy's economic cost up to $50 billion

The Red Cross has received some big corporate donations in the wake of the storm. Companies that have pledged to give $1 million or more include: JPMorgan Chase (JPM), Walt Disney (DIS), News Corp (NWS)., Kohl's (KSS), Morgan Stanley (MS), Mercedes-Benz USA, and Enterprise Holdings Foundation.

As of midday Friday, businesses had contributed more than $38 million in cash and employee-matching or customer-matching programs to the Red Cross and other relief agencies, according to a tally from the U.S. Chamber of Commerce.

Meanwhile, performers including Bruce Springsteen, Jon Bon Jovi, Christina Aguilera and Billy Joel will use their star power to solicit Red Cross donations at a benefit concert hosted by NBC, airing Friday at 8 p.m. ET.

How to help

If you'd like to donate to the Red Cross online, go to www.redcross.org. You can also mail a check to: the American Red Cross, P.O. Box 37243, Washington, D.C., 20013. To donate by phone, call 1-800-RED-CROSS or give up to $10 by texting the word "REDCROSS" to 90999.

Visit CNN's Impact Your World for more information about the best ways to help hurricane victims, as well as how to volunteer for cleanup efforts.