Aziz Ansari is the latest “Parks and Recreation” star to pay tribute to Harris Wittels, the NBC show’s co-executive producer who died on Thursday of a possible drug overdose.

Ansari dedicated a Tumblr post to Wittels, whom he described on Facebook and Twitter as a “friend, colleague & hero” on Friday.

“There are so few people that you meet in life that give you that feeling that you’ve found a real unique, original person,” he wrote. “Harris Wittels was one of those and we lost him yesterday.”

The comedian reminisces about first meeting Wittels when he was working as a stand-up comic, then talks about how his writing career took off.

“I’m still waiting for the other phone call to let me know that Wittels is okay and this was all a horrible misunderstanding,” Ansari wrote. “I don’t know when my brain is going to be able to process the terrible feeling that fills my heart with dread and my eyes with tears every 20 seconds when I realize this very special person is really gone.”

He also shares stories about the two films that they collaborated on, which Wittels wrote, “that never saw the light of day.” Read the full message here.

Ansari’s co-star Amy Poehler honored Wittels at Variety’s second annual unite4:humanity event, hours after learning about his death on Thursday.

“Today, I lost a friend,” she said. “I lost a dear, young friend in my life who was struggling with addiction.”