FDA and reports put out all the info to inform the masses, it's pretty much government disclaimer that you can die from it, but it's legal so use at your own risk.
"NOBODY" may not die directly from marijuana use, though I'm sure plenty have died from driving under the influence of it or something else that is stupid.
This is a funny argument because if you look it up you will find that there are chemicals in cig smoke that are put out that have yet to be identified...so no they aren't disclosing everything about it.
Marijuana on the other hand has had all of it's chemical output from smoking identified and none have anywhere near the carcinogenic quantities that tobacco does.
Driving under the influence is a blanket law covering the influence of everything from alcohol to weed to prescription pills. Usually with weed you end up 15 under the speed limit and a blinker on 2 miles before you turn.