After 15 successful seasons, CBS’ hit crime show CSI: Crime Scene Investigation will say farewell with a two hour finale on Sept. 27 — and the show’s loyal fans aren’t the only ones having a tough time saying goodbye.

“I got tears when I least expected them to come, at a crime scene,” original castmember Marg Helgenberger (Catherine Willows) confesses of the reunion. “Catherine/Marg is not as tough as she seems.”

'csi' cast

The CSI cast at the People's Choice Awards in 2004.

“We hope we’ve done a good enough job saying thank you,” gushes her co-star William Petersen (Gil Grissom), who, along with Marg, returns for the final episode.

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But the misty-eyed actors have had their share of laughs over the years as well. “Dr. Robbins autopsied a bear, a shark, a rat and a sumo wrestler,” notes Robert David Hall, who played the Las Vegas lab’s M.E. “It was always fun.”

The grisly plots often led to gallows humor. “Not only did we love being part of a groundbreaking show,” says Marg, “but we thoroughly enjoyed each other’s company.”

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