Historic floods have hit southern Louisiana, leaving tens of thousands in shelters, 40,000 homes destroyed and at least 13 dead.

>> PHOTOS: Thousands rescued from 'historic' Louisiana floods

Caskets have been seen floating down streets.

>> Caskets float down Louisiana streets after historic floods

The National Oceanic and Atmospheric Administration has classified the flooding as a once-in-every-500-years event.

>> Louisiana flooding: What is a 500-year flood and why is it happening so much?

Amid the devastation, there have been glimpses of humanity.

>> Read more trending stories

Frank Relle wrote on Facebook:

"I went out to the flooded areas yesterday because I have a boat and I thought I could help. I found without proper planning, good information and coordination with local government agencies my efforts like those of countless other rescue boats ended in frustration and disaster sight seeing that put ourselves as rescuers in harms way. It's tough wanting to help so badly and not really being prepared to do so. The destruction to people's property was mind boggling but the overwhelmingly positive human spirit and desire to help others made a bigger impact on me. Today I've tried to organize and share information for rescue efforts. I hope it did some good and hope everyone who is still struggling with this crisis finds peace and some security soon. ‪#‎laflood‬ thanks @mahyowie for always being up for anything."

>> Click here or scroll down to see the videos