Yes, water can burn, but not using oxygen as an oxidizing agent. See http://pipeline.corante.com/archives/2008/02/26/sand_wont_save_you_this_time.php, noting especially the quote:
It is, of course, extremely toxic, but that's the least of the problem. It is hypergolic with every known fuel, and so rapidly hypergolic that no ignition delay has ever been measured. It is also hypergolic with such things as cloth, wood, and test engineers, not to mention asbestos, sand, and water-with which it reacts explosively. It can be kept in some of the ordinary structural metals-steel, copper, aluminium, etc.-because of the formation of a thin film of insoluble metal fluoride which protects the bulk of the metal, just as the invisible coat of oxide on aluminium keeps it from burning up in the atmosphere. If, however, this coat is melted or scrubbed off, and has no chance to reform, the operator is confronted with the problem of coping with a metal-fluorine fire. For dealing with this situation, I have always recommended a good pair of running shoes.”
Not only will water burn with ClF3, it will spontaneously burst into flame!
Information about American English usage here and here. Floating point issues? Please read this before posting. — emc