[3][4] The suspension chain was tied back to the bank and ran over the tops of two sets of pyramidal cast iron towers, on piled foundations, some 92 feet (28 m) apart.

[4] This had not originally been intended and, to provide sufficient width for two carriages to pass each other, the bridge was widened by some 2 feet (0.61 m) on each side in 1844.

[6] Cooke's Royal Circus was in Great Yarmouth, and as part of a promotion, it was advertised that a clown, named Arthur Nelson, would sail up the River Bure in a washtub pulled by four geese on 2 May 1845.

[7] Several thousand people viewed the clown from the river banks and at least 300 in a crowd 4–5 deep on the southern footway of the bridge.

[11][6] At around 5.40 pm, one of the eyebars in the southern suspension chain failed; members of the crowd witnessed this, but no action seemed to have been taken to evacuate the bridge.

[5] The south side of the deck fell into the river, though the north end remained suspended by the surviving chain, and the majority of the crowd were tipped into the water, which at this point was 7 feet (2.1 m) deep.

[12] The wounded and dead were taken to nearby houses and pubs (including the Norwich Arms, the Admiral Collingwood and the Swan).

[7] Some 75 bodies were recovered on the day of the accident, though some remained trapped in the wreckage of the bridge – one man was rescued alive sometime later after being freed with a crowbar.

[7] The British government commissioned a report by James Walker, past-president of the Institution of Civil Engineers (ICE).

[1] Walker found that Scoles' original specification correctly called for high-quality iron to be used for the eyebars but failed to specify any testing of the product.

[14] Norwich ICE member William Thorold visited the scene of the accident on 3 May to inspect the wreckage and on 20 May presented a report on the matter in the Proceedings of the Institution of Civil Engineers.

[11] Thorold considered that the increased width was a factor in the failure but that the principal cause was faulty quality in the suspension chain.

[3] Indeed, crowds of 2–3 times as many people had previously been present on the bridge, but the loads had been spread more evenly across the two suspension chains.

He noted that a similar bridge at Montrose, Angus had collapsed when a crowd formed on it to observe a boat race.