From CNN:
Tarek Fahim was taking videos of the water filling behind the dam in the Derna valley in Libya late Saturday night. Up until 1:30 am, Storm Daniel was just wind and rain. When he went home an hour later, it took very little time between the moment he heard the dam burst and the gushing water flooding his street.
“The amount of water and the cars it was pushing felt like an earthquake,” he says. He moved the family to the rooftop, and they climbed up a water tank as the water kept rising. They survived. “Maybe one percent of those who lived on ground floors survived,” he says of his neighborhood around al-Fanar street.