Public Service Announcement: Yo, you seriously should not put water on a grease fire because, as this video demonstrates, you will get caught in a scary, slo-mo flame cloud.
If they still had Home Ec class when you were in school, you probably had some terrified teacher explain, with frantic waving hands, that you should never, ever put water on a grease fire. But since you were such a cool dude back then, you were probably like, "Whatever, teach!" Then you went out back and smoked 15 cigarettes while doing donuts in your car because that's what a badass you were.
Well, as The Slo Mo Guys are here to show us, your teacher was RIGHT! (She probably also had a really good blueberry muffin recipe that you totally ignored, too.) In beautiful, HD slow motion, they show us exactly how f*cking scary a grease fire is — very f*cking scary.
In conclusion: keep a fire extinguisher in your kitchen.