Which was the only Thames bridge to have been damaged by German bombing during the Second World War?

Although London suffered extensive damage during WW2 bombing campaigns, most of the bridges over the Thames remained intact. Waterloo Bridge in central London was the exception -- it was hit on 10 May 1941.

But, ironically, it was not even a functioning bridge at the time.

The original Waterloo Bridge had opened in 1817, but by the 1920s was suffering from erosion caused by the river Thames and from the cumulative stress imposed by traffic that had not been imagined in the 19th century. So the original bridge was demolished in 1937 and soon after work began on the present-day version. Construction in early WW2 was slowed by the labour shortages (this was resolved by employing mainly female labourers, giving it the nickname 'The Lady Bridge') and so the German bombs hit a work-in-progress.

Following the 1941 bombing, the new Waterloo bridge was partially opened on 11 March 1942 and was completed in 1945.