Pilot yelled 'mayday' before shopping centre crash

A pilot repeatedly yelled "Mayday" but did not say what the emergency was before his plane crashed into the roof of an Australian shopping centre, killing himself and four American tourists, an accident investigator has said.

Police blamed "catastrophic engine failure" when the twin-engine Beechcraft B200 Super King Air crashed into the Direct Factory Outlet mall in the Melbourne suburb of Essendon on Tuesday, moments after take-off from a nearby runway.