It's a sad day for the world, as environmental activist Mark Baumer has died, after getting struck by an SUV in Walton Country, Florida, while attempting to walk barefoot across the United States. According to the Daily News, he was over 100 days into his barefoot journey, a protest against climate change, when he lost his life.

Baumer was walking to raise awareness and funds for the FANG Collective, "a Rhode Island organization that supports nonviolent resistance to the natural gas industry." Prior to the journey, Baumer was working as a web content specialist at a library in Providence, Rhode Island. He graduated from Brown University in 2011.

Baumer had already walked across the United States in 81 days back in 2010, but he was wearing shoes during that journey.

Baumer has been remembered online by the FANG Collective as "an amazingly compassionate, emphatic, humble, joyful, generous, mindful and caring person."

Check out a few of Mark Baumer's final Instagram posts below. RIP