It is possible to be killed by too much marijuana, and here's the proof.

A man was travelling thru Brazil just the other day and refused to stop for a Federal Police Roadblock. Then the chase was on. Just three miles down the road he lost control of his car, and crashed into a tree. That's when the half-ton of marijuana in the back of his car was thrown forward crushing the man to death against his steering wheel. The man has not been able to be identified as he had no I.D. on him, but police are still investigating.

[News Vine]