Taping the Cory Monteith tribute episode was "incredibly difficult" for the cast and crew of "Glee," and "very rough" for the actor's co-star and girlfriend Lea Michele, producer Ryan Murphy told People.com.
"People are still not over it. It is still really difficult," Murphy said. "I've never seen a crew that can't continue shooting because they left the room sobbing. What you're seeing is what they felt not just about Finn, but Cory."
TMZ reported earlier this week that the official coroner's report said 31-year-old Monteith died from an overdose of heroin and alcohol. The actor, who had battled substance abuse problems for years, was found in July in a hotel room in Vancouver, Canada.
Murphy said Monteith's death has been devastating for Michele, who was his girlfriend both on the show and in real life.
"It was very rough," Murphy said of shooting the episode with 27-year-old Michele. "It was very rough with Lea."
Murphy said the episode -- the trailer of which shows the crying cast gathered around Finn's locker -- is titled "The Quarterback."
"The actors and creators really loved Cory ... and Cory really was 'The Quarterback' to that group of people," Murphy said. "There was nobody on that crew that did not like Cory. He was the most kind, the most generous, never a bad word for anybody."
Murphy said filming was "tricky" and there was "no right way" to do such an episode.
"I think the performances are quite stunning," said Murphy, who also wrote the episode. "Honestly, almost everything from that episode is from the first take -- of every performance -- because the actors and the crew had a really hard time shooting it. But I am very proud."