Our warning came to pass. Don't mix Vinegar and bleach!
Sometime ago, I wrote of how it wasn't the best idea in the world to mix bleach and vinegar (August 27th, 2014). The result of this is chlorine gas.
However, it appears someone in Bristol didn't take heed of it, alas, and attempted to clean a bath by what I susupect was this method (the emergency services didn't confirm it, but from the account of the event it seems likely).
The full story can be found here, and detail how the fire crews used specialist equipment to empty the flat of the gas. It is fortunate that no one was seriously hurt.
They end the article by saying that you should follow a simple principle: NEVER mix cleaning products with anything other than what the instructions say.