One Year After The Tornado, Celebrating Joplin's Animal Heroes (VIDEOS)

On May 22, 2011, one of the worst tornadoes in US history hit Joplin, Mo., killing 161 people and destroying nearly a third of the city.

It was a devastating time. Yet, amidst the grief and widespread destruction, the city of Joplin has shown a resilience and hope that has been astounding.

On the first anniversary of the tornado, the city will come together in a "walk of unity" as they remember the steadfast togetherness that has kept them strong and the heroes that helped saved lives.

But Joplin's heroes come in many sizes: male and female, young and old, on two legs and on four.

Here, we celebrate the animal heroes of the Joplin tornado -- pets who have worked tirelessly to save survivors or to retrieve victims, as well as animals who've bravely endured the challenges of the disaster, offering hope to a city in recovery.