From BBC report:
https://www.bbc.co.uk/news/world-europe-57858829
"In the western German district of Ahrweiler, up to 1,300 people are unaccounted for, the authorities say. A spokeswoman for the local government said mobile networks had been put out of action, making it impossible to contact many people."
and
"Even the authorities say they don't know for sure how many people are missing. There is no phone signal in much of the region, making communication all but impossible. But the death toll is expected to rise today and with every hour that passes the magnitude of this disaster becomes ever clearer.
All along the River Ahr there are flooded homes, broken bridges, the twisted remains of campsites and caravan parks. For many of the dazed people we met surveying the damage here, it's almost impossible to imagine clearing up and starting again."