Communication networks across the Northeast were slowly recovering Thursday, but many New York and New Jersey residents were still unable to make cell phone calls as wireless providers scrambled to repair equipment damaged by Hurricane Sandy.

In a statement Thursday afternoon, officials from the Federal Communications Commission said they were noticing “steady improvements” in telecom networks in areas affected by the storm, but that “much work remains to be done to restore service fully.” They did not give an estimate on how long it would take for wireless service to fully recover, though on Wednesday they said it could take several days.

“Replenishing fuel supplies for generators that are enabling communications networks to continue operating is a particularly critical challenge,” David Turetsky, the FCC’s public safety and homeland security bureau chief, said in a statement.

FCC officials also said calls to 911 centers were largely working, though some were still being re-routed to other centers or did not include location information, meaning callers would have to explain where they were to dispatchers.

Meanwhile, major wireless providers were scrambling to repair damage to their equipment. In a statement Thursday, Verizon said employees were still repairing broken utility poles, damaged cables and water-damaged electronics, and the availability of fuel to keep generators delivering backup power to network equipment was “an increasing challenge in hard-hit areas."

AT&T spokesman Mark Siegel said Thursday that the “vast majority" of the company's cell transmission sites in the Northeast were online and working, but did not give specific numbers of customers lacking service or when they could expect it to be restored.

He said the company's disaster response teams were making progress restoring wireless and wireline services in hard-hit areas, including New York City and New Jersey, where flooding, debris, loss of power, and transportation difficulties were posing problems.

Sprint said about 20 percent of its network in New York, New Jersey and Connecticut was down. T-Mobile said 15 percent of its wireless network in New York City was not working.

AT&T and T-Mobile said Wednesday they were taking the unusual step of allowing their customers to use each other's networks in New York and New Jersey until their networks were fully restored. And New York City Mayor Michael Bloomberg said Thursday that AT&T had promised to send satellite trucks that would serve as "hot spots" for wireless customers without service.

Telecom infrastructure experts said there was little that wireless providers could have done to prepare for a storm of this magnitude and avoid outages.

“There is no such thing as a wireless network that’s going to stay up 100 percent of the time when you have a storm this severe," said Andrew Seybold, a wireless industry consultant who has worked for wireless carriers in the past but said he does not currently have contracts with any of them.

He said wireless providers were grappling not just with equipment damage from the storm, but also wireless networks that quickly become overloaded as millions of customers tried to make calls all at once.

While wireless providers worked to restore service, thousands of New York and New Jersey residents still struggled to get connected.

Hoboken resident Jeffrey Lacouture said both of his cell phones –- one on AT&T's wireless network, the other on Verizon's -– lost service within an hour after he lost power Monday night, preventing him from checking for news updates on Twitter or letting his family and friends know that he was safe.

“When word got around that Hoboken was flooded, people tried to text me to say ‘Hey, are you okay?’ but I wasn’t able to get through,” he said. “I couldn’t reach them, and they started worrying.”

Adina Bresge, a 20-year-old student at New York University, said she still did not have cellular or 3G data service from AT&T where she lived in East Village. Since Monday, she has been unable to do more than send occasional text messages on her phone unless she travels north of 28th Street in Manhattan.

"It's getting better by the day," she said. "Today I got a bar in my apartment, which is a novelty."

But she said the sporadic connectivity has made it difficult for her parents to reach her since the hurricane made landfall.

"It's been stressing my parents out," she said. "They've been been worried sick."

*************************

The Huffington Post is eager for insights from our community, especially people with experience in power, infrastructure and engineering, on the adequacy of emergency preparation in advance of Hurricane Sandy, and the degree to which past disasters have informed adequate planning and construction. Please send a note to sandytips@huffingtonpost.com with insights and suggestions for the important questions that need to be asked of relevant private sector and government officials, and point us toward stories that need to be pursued.

Earlier on HuffPost: