Marijuana is not a dangerous drug. Period.
No one - ever - has been killed by smoking too much weed. You can OD on aspirin, which is sold over the counter - to kids, yet. You can OD on most of the pills you can buy at your local pharmacy. But you cannot OD on weed - it's one of the least harmful substances on the planet.
Wanna see a real dangerous drug? Here ya go . . .