Harris Wittels, an executive producer on NBC’s “Parks and Recreation,” died Thursday of a speculated overdose. The EP was 30-years-old. As police investigate Wittels’ death, the cast and crew of the comedy have begun to speak out about their late coworker.

Amy Poehler, star of “Parks and Recreation,” chose to address Wittels death while speaking at a Unite4Humanity event in Beverly Hills on Thursday. The normally funny Poehler was somber as she told the audience about the loss she endured earlier in the day.

“So today, I lost a friend,” Poehler told the audience, according to Us Weekly. “I lost a dear, young man in my life who was struggling with addiction and who died just a few hours before we came. Jane [Aronson] and I sat and talked about it, and I’m sharing it with you because life and death live so closely together and we walk that fine line every day. At the end of the day, when things happen in our lives and we turn to people that we love and we turn to family and community for support, we lean on people and hope that they will ease our pain.”

Poehler also mourned Wittels through her side Twitter account, @smrtgrls. Her post was retweeted by “Parks and Recreation” co-star Aubrey Plaza:

Other cast and crewmembers of the NBC series took to Twitter to pay their respects:

According to USA Today, Wittels was found unresponsive in his Los Angeles home Thursday afternoon. Police responded to a “possible drug overdose.” TMZ reports that he had been to rehab twice, and spoke about his sobriety while doing stand-up comedy the night before at The Meltdown, a Los Angeles theater.

Wittels was not only an executive producer on "Parks and Recreation." He was a writer and featured in a couple of episodes, as well. His last on-screen appearance was in the Feb. 10 episode, "Pie-Mary." Harris Wittels was also known for working on shows like "The Sarah Silverman Program," "Secret Girlfriend" and "Eastbound and Down."