An environmental activist and prominent gay and transgender rights attorney committed suicide by setting himself ablaze in Brooklyn’s Prospect Park in a shocking protest over what he called the Earth’s ecological destruction, the New York Post reported.

What did his suicide note say?

Next to the charred remains of David Buckel, 60, was a typed suicide note that explained he burned himself to death with fossil fuel to "reflect how mankind was likewise killing itself,” according to reports.

The note was in a manila envelope marked “To the Police,” and was placed inside a black metal pushcart Buckel left at the scene. The note was also sent to the New York Times, the report states.

“Most humans on the planet now breathe air made unhealthy by fossil fuels, and many die early deaths as a result,” Buckel’s note stated. “My early death by fossil fuel reflects what we are doing to ourselves.”

“Honorable purpose in life invites honorable purpose in death,” he added.

Buckel’s protest on Saturday created a horrifying scene for passersby, the Post reported.

“It’s a shock; it’s a shame,” said mom Dana Lall, who was leading a group of Catholic-school kids past the scene on their way to a baseball game.

What cases had Buckel worked on?

Buckel was a senior attorney with Lambda Legal defense. He served as the lead attorney in a 2000 lawsuit on behalf of transgender “Boys Don’t Cry” rape-murder victim Brandon Teena.

Hilary Swank earned an Oscar for her role of Teena in the 1999 movie by the same name.

“It’s a very important case, not only within Nebraska but nationally,” Buckel had told the Daily Nebraskan newspaper in 2001. He had also helped the family win an $80,000 judgment, the Post reported.

“This is a tremendous loss for our Lambda Legal family, but also for the entire movement for social justice,” the organization tweeted Saturday night.

Buckel was involved in a series of other high-profile cases, including a New Jersey Supreme Court ruling in 2006 that recognized gay couples as having the same legal rights and financial benefits as heterosexual married couples.

More recently, Buckel was an urban gardener and ecologist with the Brooklyn Botanic Garden. He ran was he called the largest composting program in the country that used renewable sources of energy, the Post reported.

“There’s no denying that sticking with renewable resources means a lot of elbow grease with pitchforks and shovels,” he wrote in a 2016 article on the Botanic Garden Web site. “But it is incredibly satisfying work.”