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.

At least 87 people are dead after heavy rain led to "catastrophic" flooding in Texas. Kerr County was hit the hardest, with at least 75 deaths, including 27 children. President Donald Trump signed a disaster declaration for the county and the Federal Emergency Management Agency is on the ground there.

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.