Another one you'll see FDNY use ALL the time - they have what is basiclly a chainsaw that has a 12" or so abrasive cutoff blade (they also have chainsaws and the circular saw with regular saw blades)

The want in, they have no qualms about cutting their way in. Lets face it - they probably respond to a bunch of "taxpayer" (small storefront) fires every day, and there are roll down steel gates with locks - out come the saw - zip, there goes the lock. I've actually seen them throw a chain around something that needed to come down, throw it around the bumper of the engine, and yank