by BBC Midlands Home Affairs correspondent Peter Wilson
The Real IRA team broke a 27-year unwritten order when they plotted to bomb Birmingham city centre.
The gold Audi coupe was packed with explosives
The men parked a gold Audi coupe packed with home-made explosives just a few hundred yards from where two pubs were destroyed by bombs in 1974, killing 21 people and injuring more than 170.
The backlash meant Birmingham was out of bounds for terror attacks - but the hardline splinter group Real IRA refused to observe the code and pressed ahead with plans for the car blast in the city.
Luckily, the bomb detonator went off but the home-made explosives failed to ignite.
People were afraid to say what they thought it was even though we knew that most people thought it was anthrax
Two British Transport Police were only yards away when the device was triggered - and they were peppered with the explosive mixture.
Acting Sergeant Colin Janes said they thought they had been contaminated with anthrax.
"We heard this almighty bang through the vehicle, it felt like a solid thud.
"Then there was a lot of powder in the air which we breathed in."
Pc Jesbir Kumar said: "People were afraid to say what they thought it was even though we knew that most people thought it was anthrax."
The two officers helped to evacuate nearby buildings and cleared the area.
Police were covered in the explosive mixture
About 10,000 people were in nightclubs and restaurants on the busy Saturday night in November 2001.
West Midlands Police said the bomb was the same size as the one which destroyed Manchester City Centre in 1996, injuring 300 people.
The car was a goldmine of forensic information and contained a jacket belonging to one of the bombers.
The bomb timer and power unit also proved to be valuable evidence.
Eleven days later the police arrested the Real IRA team responsible for other bombs set outside a pub in Ealing and the BBC TV studios in London.