At Camp Mystic, a Christian summer camp in Hunt, Texas, where officials are grieving the loss of 27 children and counselors, belongings of the young campers were strewn about the flooded floors of a dormitory, while other items, including a pink backpack and a Camp Mystic T-shirt, were found along the bloated Guadalupe River, photos show.

Here’s what to know about the deadly flooding, the colossal weather system that drove it in, and around Kerr County, Texas, and ongoing efforts to identify victims.