Have you ever been in a bar and watch someone stagger out? Did you think about what might happen? Did you think the barkeep should have thought of that, and stopped serving?
Dram shop laws hold businesses responsible when they keep serving alcohol to someone a reasonable person would realize should not have another drink, and the inevitable happens.
To prove such a claim the injury victim must be able to show that the at-fault driver was apparently intoxicated. In other words, they seemed drunk to others. This can be trickier to prove than it you might think. Some people seem sober at first when they are not, and this is often true of heavy drinkers. You can guess what the bartender will say, even under oath.
The blood-alcohol level of the driver, while important evidence, may not be enough proof.
That is why it is important to talk to a personal injury attorney early. Witnesses and other evidence must be gathered quickly while it is stil possible to do so.