Aid organisations have stressed the need for an independent investigation into the deadly Israeli drone strike on an aid convoy after the IDF published its first account of the event.Also in the programme: The BBC's analysis of Israel's evacuation warnings in Gaza; we remember the Nirvana singer, Kurt Cobain, thirty years after his death; and will a new currency stabilise Zimbabwe's economy?(Photo: Clothes of members of the NGO World Central Kitchen (WCK) inside their destroyed car in southern Gaza Strip. Credit: EPA).