The departure of  Marg Helgenberger’s character Willows on Wednesday night’s 10 p.m. episode of CSI drew killer numbers on CTV with 3.11 million (2+) viewers watching the show, according to BBM Canada numbers provided by CTV.

Over 1.2 million of those viewers were in the 25-to-54 demo.

According to CTV, the episode was the most-watched for the series since January 2009.

CTV also posted big numbers at 8 p.m., with 2.31 million (2+) viewers watching American Idol. The episode was up 24% over last week’s with people aged 18 to 34 and up 10% in the 18-to-49 demo.

Criminal Minds at 9 p.m. also hit a milestone, earning a season-best 2.45 million viewers (2+), according to BBM Canada numbers provided by CTV.

From Media in Canada