Anne Wilson, head teacher of Fircroft Primary School in Tooting, has paid tribute to pupil Imani Green, who was shot dead in Jamaica during a family visit to the country.
"The entire Fircroft School community is deeply shocked and saddened by the tragic news of the death of our pupil Imani Green. Our thoughts and prayers are with her family to whom we pledge our continuing love and support."
More top news
The plaque at number 16 Cowley Street in Westminster marks the brown brick Georgian townhouse where Sir John lived for 31 years.
A man reportedly armed with several knives has been arrested in Whitehall on suspicion of planning a terror attack, police have said.
Metropolitan Police officer, Tom Harrison, has been crawling the course since the race began on Sunday morning.