CHICAGO (CBS) — The man who asked repeatedly for a state investigation into the Sterigenics plant in Willowbrook was remembered Saturday at a vigil in Elmhurst.

Hundreds came out to honor Matt Haller, who died of stomach cancer in March. Saturday would have been his 46th birthday.

READ MORE: Chicago Weather: Rounding Out The Warmest Weekend Of The Winter

Haller wanted everyone to see the pain he was going through, and he was featured in many of CBS 2’s exclusive investigations into ethylene oxide emissions in Willowbrook.

The Environmental Protection Agency ultimately put a seal order on the plant which sterilizes medical equipment.

READ MORE: MISSING: Khoshaba Dikyanos, 84, Last Seen In Lincoln Square

Haller is survived by his wife Colleen and his son Cullen.

A GoFundMe page has been created to support the Haller family.

MORE NEWS: Chicago Speed Cameras To Start Issuing $35 Tickets To Drivers Going 6 MPH Over The Limit On Monday