All the major cell phone carriers here in New York say their networks are having issues due to Sandy

Federal regulators say the storm knocked out a quarter of the cell towers in an area across ten states. 

AT&T confirms it is experiencing  “some issues in areas heavily impacted by the storm.” AT&T and T-Mobile have entered into an agreement to enable roaming on their networks to customers of both companies. Calls will be carried by whichever network is most operational in their area.

Verizon Wireless, the largest cell carrier in the country, said their network in greater New York has been stressed due to flooding and power outages and that there are "serious problems" in lower Manhattan. They are working to restore service, but did not release an estimate of when they expect repairs to be completed.

Cell phone networks get hit two ways during a natural disaster like this. First the have this big towers with lots of sensitive equipment on them that are just primed for wind damage. Then, have power issues. Some towers have backup power or generators — especially after Hurricane Katrina —but still might only have backup power to run for a certain number of hours.

The second big issue is overwhelming usage of cellphones. After a disaster like this we all want to talk to our friends and family. Many people no longer have landlines, so there's a demand issue on top of equipment issues.

According to industry researchers, companies certainly know which towers are up and which towers are down. They may not know earlier is why a specific tower isn't working, but they certainly know from a coverage perspective what's working and what's not.

Carriers say that in some cases, they may have to wait for power companies to restore service.

If you're having problems with cellular service, tell us about it on Twitter with the hashtag #sandycell.