...died of pneumonia, not an overdose, rules the Los Angeles County Coroner:

Although the investigation into Haim's death began as a "suspected prescription medication overdose," toxicology tests "revealed no significant contributing factors" from drugs, the coroner reported.

The autopsy found "an extremely large amount" of swelling in Haim's lungs, it said. [...]

Haim died March 10 after collapsing at the Los Angeles apartment he shared with his mother.