Well-know LGBT rights lawyer David Buckel killed himself in Propsect Park Saturday morning.

“I am David Buckel and I just killed myself by fire as a protest suicide. I apologize to you for the mess.”

That was what was handwritten on a note left for police inside an envelope near the body of the well-known civil rights lawyer in New York’s Prospect Park around 6:30 a.m. Saturday, April 14, according to the New York Daily News.

In another note found near his body — and also emailed to several news outlets — Buckel explained that he was setting himself on fire as a protest suicide to bring attention to environmental issues.

He wrote: “Pollution ravages our planet, oozing inhabitability via air, soil, water and weather. Most humans on the planet now breathe air made unhealthy by fossil fuels, and many die early deaths as a result — my early death by fossil fuel reflects what we are doing to ourselves. … I hope it is an honorable death that might serve others.”

Buckel was well known for his efforts toward marriage equality and on other LGBT rights issues. He was lead attorney in the lawsuit involving transgender murder victim Brandon Teena, who was raped and then killed in 1993, in which the county sheriff was found negligent for failing to protect Teena.

MSN.com recapped several of the important cases in which Buckel participated.

In Nabozny v. Podlesny, Buckel was the attorney for Jamie Nabozny, a gay man who sued his former public high school in Wisconsin for failing to prevent consistent and significant anti-gay bullying and abuse. The court ultimately ruled in 1996 that schools have a responsibility to protect students from anti-gay abuse.

He was an attorney in Lewis v. Harris, in which the New Jersey Supreme Court unanimously ruled in 2006 that same-sex couples be provided all the benefits and responsibility of marriage. And he was marriage project director for Lambda Legal when that organization filed a lawsuit in Iowa, Varnum v. Brien, on behalf of same-sex couples in which the Iowa Supreme Court ruled in 2009 that denying same-sex couples the right to marry was unconstitutional, a decision that made Iowa the third state to legalize same-sex marriage.