In 1987, sudden and intense rainfall caused the river to surge at an unprecedented rate in mid-July, leading to a tragedy that killed 10 campers at Pot O' Gold Christian Camp, a summer camp near Comfort, Texas. The campers drowned when their bus attempted to evacuate them and was overtaken by floodwater.

Search efforts continue for the dozens of people still missing after Friday's floods, as questions swirl over what went wrong. Here's what we know so far.

Rescue operations are ongoing in Central Texas after flash flooding along the Guadalupe River left 23 girls from Camp Mystic unaccounted for. Officials say dozens have died as catastrophic floods continue to ravage the Hill Country.