Days after flash floods killed over 100 people during the July Fourth weekend, search-and-rescue teams are using heavy equipment to untangle and peel away layers of trees, unearth large rocks in riverbanks and move massive piles of debris that stretch for miles in the search for the missing people.

Kerr County, Texas, lacked a “last mile” warning mechanism that could have saved residents before the deadly floods devastated the area, including a children’s summer camp, killing more than 80 people.