On August 21, 2016, Carissa posted photos on social media of a devastating flood in Louisiana. The next morning she included a note from someone in the flooded area pleading for help. Five hours after that, she and her husband, Bobby, sent out a call for others to join them on their 1,000-mile trip to provide help. Less than twenty-four hours later, thirteen people were on their way to serve those whose homes had been severely damaged.

What motivates people to drop everything and drive seventeen hours to move appliances, do demolition work, and provide hope in a place they’ve never…