So, so sad.
Here's what TMZ is reporting:
When help arrived, paramedics found 34-year-old Kelly lying on the living room couch -- unresponsive and with "no life signs." The medics attempted to revive Kelly, to no avail.
Kelly was immediately transported to a nearby hospital, where he was pronounced dead a few hours later.
After the death, cops spoke with Donna Kelly Pratt -- Chris' mother -- who told police ... the night before Kelly's medical emergency, he had taken a mixture of heroin and cocaine -- commonly known as "speedballs."
Read more here.