It's official: Heath died of an overdose of prescription drugs, totally accidental.

His family is a real class act.  They released a statement which included the following heart-wrenching, poignant, and graceful words:

We remain humble as parents and a family, among millions of people worldwide who may have suffered the tragic loss of a child. Few can understand the hollow, wrenching, and enduring agony parents silently suffer when a child predeceases them. Today’s results put an end to speculation, but our son’s beautiful spirit and enduring memory will forever remain in our hearts.