“Yesterday was a warning bell in the night that tells us there is something terribly wrong with 911. The whole point of 911 is to be able to get through,” said former FCC Chairman Reed Hundt, who led the commission in 1996 when it required wireless carriers to implement basic 911 services.

FCC officials did not like what they saw. They’re asking wireless providers to explain the extent of Tuesday’s logjam and what can be done to prevent it from happening again.

“It’s a serious concern for us,” one FCC official told POLITICO. “We have a lot of people now who cut the cord, and who rely on their wireless phones to reach loved ones. If there are problems with that, it’s something we need to investigate.”