Wrong chemical...
...I was sent to standby (paramedic) at a "dangerous chemical spill" until the fire service officers could declare the scene safe. This was a major incident and took about 11 hours to render safe, so it attracted a lot of media attention etc. A young and rather excited rookie police officer turns up early on and asks me what the chemical is and I tell him it is Ammonium Nitrate – I assumed he would know of this industrial fertilizer and it's potential for explosion as it can be used in terrorist bombs (as in the Oklahoma City bomb a few years ago).

Maybe he wasn’t listening to me properly.

He got on his radio to his sergeant and states “It’s been confirmed as Amyl Nitrate and it’s all over the highway”. The two drug squad officers who turned up a short time later were not impressed with what they found.
(emadex thinks the world will end on, Sun 9 Jan 2005, 17:11, Reply)