From a story on cjr.org by Jon Allsop headlined “The silence and the noise”:

Late Friday, Gaza was plunged into darkness. Phone and internet lines went down across the territory, stopping the outside world from communicating with its residents and its residents with one another. As Israeli bombs rained down, emergency workers located casualties by following the sounds of explosions.

Anonymous US officials told the media that they believed Israel had shut off communications in Gaza, and claimed that they urged their Israeli counterparts to restore them. Publicly, various international observers did likewise. “A communications blackout,” the Committee to Protect Journalists pointed out, is also “a news blackout.”