GENERAL KNOWLEDGE: Sarcastic remark, clever saying?

Questions

What is the name of the 22 storey Canning Town tower block that collapsed in 1968?

London, to whom is the Cross at Charing Cross a memorial?

What is the address of the Sherlock Holmes museum in London?

What area of London is bounded by Oxford St, Charing Cross Rd, Coventry St and Regent St?

Who led the army of Britons who razed London to the ground in AD 60-61?