The twenty three-year-old woman was working as one of the contracted security providers for the gig at the 02 Academy in Brixton, south London, on Thursday evening.
The Metropolitan Police said in a statement that a third woman, aged twenty one, was in hospital in a critical condition.
Chief Superintendent, Colin Wingrove, in charge of the investigation, called the second death devastating news and sent his condolences to the woman’s family.
