I had just begun breakfast on September 16, 2018, when we received the radio call. A flood pulse was coming. It would reach us in 30 minutes.
Photo assistant Jeff Wade and I were camped some 6,890 feet below ground with members of the Perovo-Speleo caving team, an elite group of Russian cavers who are pushing the boundaries of exploration. We’d been underground for 11 days in the deepest known cave in the world: the Veryovkina system in Abkhazia, a self-declared republic in the country of Georgia. Two days earlier I’d taken the photograph you see above of expedition leader Pavel Demidov climbing out of the terminal sump, the cave’s deepest point. (See more photos from this expedition.)
Flood pulses—when a sudden accumulation of water bursts through any opening it can find—happen often in caves, and at first we weren’t concerned. (We learned later that there’d been a week of rain above ground.) Our eight-person tent was pitched in a side passage halfway up a chasm. We thought we’d be out of the way of the main flow of water. We continued with our breakfast.