An actor and one of CBC's former comedy writers has passed away.

Mike O'Brien, 51, died of cancer Sunday night.

As an actor, O'Brien appeared in several episodes of Corner Gas and Less Than Kind and wrote the book Calling the Prairies Home.

He worked for CBC Radio for 11 years as a comedy writer. In that time, he and fellow comedy writer Dean Jenkinson teamed up on many projects.

Don't go for the low hanging fruit. Just challenge yourself and maybe try and get something a little more clever. - Mike O'Brien

"It was really terrific to work with Mike. If you ever spoke to him you'd know he was a very intelligent, very funny, very, very sensitive and a keen guy," Jenkinson said Monday.

"He just had a really sharp mind and a very good sensibility about what was fair game and who to target … I learned so much from him."

Last week, O'Brien spoke with CBC's DNTO about his career in comedy and pairing with Jenkinson.

"We had a lot of fun writing … I remember once we were having a dispute and this intern started laughing. We said 'what's so funny?' and she said 'You guys have jobs where the thing that you argue about is who does the better Bugs Bunny impression.' And it was Dean, by the way," he said.

'Stunned to hear he passed so quickly'

O'Brien also worked with Kids in the Hall actor and co-creator Mark McKinney, who was in Winnipeg performing with the group last Friday at the Burton Cummings Theatre.

"He was funny as ever, he really wanted to make it down, so I gather he tweaked some inspiration and was able to make it down with some friends," said McKinney.

Sad to say, the lovely & clever Mike O’Brien - who, among many things, played Wes Humboldt on CornerGas - has passed away. <a href="https://twitter.com/hashtag/CancerSucks?src=hash">#CancerSucks</a>. —@BrentButt

"It was just fabulous to see him again. I was honestly a little stunned to hear he passed so quickly."

O'Brien was the creator behind Strange Animal, a series about human behaviour that aired on CBC's Up to Speed. It became a nationally broadcasted show but was cancelled once O'Brien developed cancer.

"Writing comedy for radio is a dream job. I don't want to do standup comedy. I don't have the makeup for it; to go and tour and play before drunken strangers. I like the idea of writing and performing" O'Brien said last week.

Corner Gas

While he appeared on several episodes of Corner Gas, he also wrote for the show for one season.

"That was real education. If I could boil it down to a few simple words it's 'make it funnier,'" O'Brien said, adding members of the show's creative team were always pushing each other to be better writers.

"That made me realize 'don't go for the low hanging fruit.' Just challenge yourself and maybe try and get something a little more clever, a little smarter."

Corner Gas star Brent Butt said he knew of O'Brien's comedic skills before he auditioned for the role of Wes Humboldt on the series.

"He was always a blast on set," Butt said from Vancouver Monday. "My relationship with Mike was just enjoying his company because he was a funny guy and relying on him as a professional because he was a funny guy," he said.

Butt said that, as the character evolved, O'Brien found new ways to improve on the jokes written for Humboldt. He recalled a scene in the series where two of the main characters, Brent and Wanda, were mocking Humboldt for wearing too much denim.

"The way that Mike O'Brien read that and put it on film was very different than how it was originally envisioned," he recalled. "He made it so much funnier than it was on paper."

Butt said O'Brien also infused Wes Humboldt with a sense of reality.

"When you find actors who can make it real ... it inherently becomes funnier," Butt said. "He just made Wes very real and very believable and as a result very funny."

O'Brien quickly became a go-to actor, he said.

"I enjoyed doing scenes with Mike," Butt said. "If we needed another local to do a funny scene, we would always see if Mike is available. Because we know that he would deliver and make it funny."

O'Brien chronicled his experiences with cancer and treatment on his blog, The Big Diseasey.

He leaves his wife and a four-year-old son behind.