Question: On what date did the tragedy that resulted in an estimated 80 deaths, and lead to Nicholas Paget-Brown stepping down as leaderof the Kensington and Chelsea London Borough Council occur?
Sentence (from "Nicholas Paget-Brown"): On 30 June 2017, he announced that he would step down as leader due to the council's response to the Grenfell Tower fire, and was replaced as leader by Conservative Elizabeth Campbell on 19 July 2017.
Relevant evidence: Yes