In the early hours of July 7, Viktor Voloshin received a panicked telephone call from his nephew, who lived with his family in Krymsk, a southern Russian city of nearly 60,000 people.
The line almost immediately went dead. But before it did, Voloshin's nephew managed to shout out that Krymsk had been devastated by a massive flood -- and that his family had barely survived.
"He said that at close to three o'clock in the morning he heard that his car alarm had gone off," Voloshin told RFE/RL's Russian Service. "When he went out, there was already water up to his knees and a box was beating up against his car. That's why the alarm went off.
"After that he quickly got himself together. He managed to get to his family, and that was it: the water hit them almost immediately. The one thing that he managed to do was save his money and some documents and then get up to the attic."
Voloshin, who lives outside the flood zone in Krasnodar Krai, jumped in his car and rushed to Krymsk.
Once there, he was unable to reach his nephew's home.
But over and over, he heard the story of how heavy rains had created a massive, 5-meter-tall wall of water that swept through the town as its residents slept.
The rushing wave overturned cars, covered houses in layers of mud, and left more than 170 people dead -- many of them children or old people.
Brief, horrifying accounts of the flood have appeared on YouTube and Twitter.
One relative of a Krymsk resident wrote, "My brother's neighbors, a family of three, all drowned. Their bodies were floating all day in their yard."
The floods raced through other neighboring towns, including the Black Sea resort town of Gelendzhik.
According to Yana Sakharova, a correspondent there with RFE/RL's Russian Service, the water levels rose with breathtaking speed, leaving the city almost completely submerged within a matter of minutes.
"It all began relatively innocently, with rains beginning at night, but after several hours of continuous rainfall, not only the coastal and outlying streets, but also the central roads, suddenly disappeared under the water," she said. "The rivers running through the roads reached a height of 1.5 meters. It was moving at such an intense speed that it was extremely difficult for pedestrians and cars to even make their way through it."
PHOTO GALLERY: The aftermath of the floods in southern Russia
On July 9, the flood-struck cities were preparing to bury many of their dead as Russia observed a national day of mourning.
But in addition to grief, there was also anger.
Many residents are questioning why, in a region prone to flooding, officials issued no warning or evacuation order even as heavy rains fell.
Some have gone so far as to suggest that local authorities purposely opened a swelling reservoir in order to redirect potential floodwaters away from the larger city of Novorossiisk.
Authorities have denied deliberately opening the reservoir's sluices, but have acknowledged that some water was "naturally" released from the reservoir because of the heavy rains.
Russian President Vladimir Putin, facing growing criticism over the slow response of emergency crews, has opened an investigation into the floods and lashed out at Krasnodar Governor Aleksandr Tkachev.
Much of Krymsk, meanwhile, remains without electricity, sewerage, or gas.
Clean water is in short supply and residents are being supplied with medicine to prevent dysentery.
The catastrophe has prompted many activists to launch online efforts to coordinate food and other aid for the flood victims.
Ulyana Kononovich, an activist based in Krasnodar, has helped gather supplies of fresh water, food, medicine, and clothing.
She maintains that most volunteer relief efforts are being carried out independently of local officials and state rescue workers:
"Our people here are professional volunteers," she said. "They know how to act in situations like this. They will ensure that all this aid gets delivered directly to the people who need it and won't disappear anywhere or get tossed out.
"People are gathering the aid now and it's lying in one place. What needs to happen now is for this to be delivered directly to people, because people are sitting at home, they're simply in shock."
Written in Prague by Daisy Sindelar, based on reporting in Krymsk by Mumin Shakirov. Arslan Saidov, Anna Ivanochkina, and Yelena Vlasenko also contributed to this report from Moscow.