After more than two decades looking down over the city centre, the end came in just two seconds.

With a clap of thunder and an almighty cloud of dust, the familiar concrete bulk of Provincial House was reduced to a 20,000-tone pile of rubble.

Hundreds of onlookers had clambered on to every available vantage point for the building's final curtain which came precisely on the last toll of City Hall's 9 o'clock chimes.

Five minutes earlier, as a warning siren wailed across the city, rows of expectant faces peered up from the lines of safety barriers and the roof of the neighbouring Hall Ings car park. With thirty seconds to go, a maroon was fired to signal the impending blast and a hush descended upon the city.

And then Provincial House went down with a deafening bang.

More than 1,500 detonating charges triggered the 90kg of explosives which had been packed into the building's major structural columns over a two-month period.

Steve Foster, operations director for Controlled Demolition Group, explained that the blast involved three separate explosions - one in the centre of the building followed by two in the ends half a second later.

"To ensure the safe demolition in the limited space, the collapse mechanism brought down the middle section of the structure first so that the outside walls were pulled inwards on the building's own footprint."

As the dust clouds from Bradford's first ever explosive demolition finally cleared, a gigantic mound of rubble and jagged concrete - around two storeys high - stood in the place of Provincial House.