The call to Greater Manchester Police control room seemed routine - one of hundreds of reports the force deals with each day.
A resident was claiming a burglary had occurred at a house in Hattersley, a suburb to the east of the city. The suspects were believed to have already fled. But while the details of the 10am 999 call appeared banal, it was a deadly trap.
The call was either made or instigated by the fugitive Dale Cregan, 29, one of Britain's most-wanted and dangerous men, whom detectives have spent the past month pursuing over fatal grenade attacks on a father and son in a bitter underworld feud.
As two unarmed female police officers approached the house in Abbey Gardens, they were allegedly fired on before a grenade was hurled at them. Constable Fiona Bone, 32, died at the scene while her colleague Constable Nicola Hughes, 23, later succumbed to her injuries in hospital.
Their deaths marked the bloodiest day in British policing for nearly 50 years - the worst atrocity since 1966 when three officers were shot dead while questioning suspects in a van in west London.
Sir Peter Fahy, Chief Constable of Greater Manchester, said it was one of the darkest days his force had confronted and said officers were "shattered" by the loss of "courageous" colleagues who, he said, exemplified the very best in British policing.
David Cameron, the British Prime Minister, led the tributes to the fallen officers. "What we have seen is the absolutely despicable act of pure evil. The cold-blooded murder of two female police officers doing their job protecting the public - another reminder of the incredible risks and great work our police service does."
Fahy said it was believed Cregan, who had been shielded by criminal followers after absconding on bail following the second grenade killing last month, deliberately lured the women to their deaths after staying at the house overnight. Two other people inside the property - a man and a woman - were later arrested.
The face of the one-eyed Cregan - who claimed to have suffered his injury as a result of a fracas with a Thai policeman with a knuckle-duster - had been plastered across billboards and beamed on to the screen at Manchester City's ground as police sought him in connection with two murders.
Following the killings, the former roofer handed himself in to a local police station where he was arrested on suspicion of four murders.
Although locals claimed rumours had been circulating in recent weeks that Cregan was living among friends in the area, police said they had no intelligence to support these claims.
However armed officers had been on patrol in east Manchester in recent weeks as they sought to recapture the suspect with the £50,000 ($98,000) reward on his head.
The deaths provoked fresh calls for the routine arming of police officers.
Officers were well liked members of squad
One of the officers killed yesterday spoke to her fiance about their upcoming wedding just before she left on her final call-out. Fiona Bone, 32, had a brief telephone conversation with her partner to discuss the design of the invitations. The couple had been "so happy", Chief Constable Sir Peter Fahy said. Fellow officers recalled a reserved young woman who joined the shift five years previously but who had flourished into a much-admired member of the team. She was a sought-after beat partner among fellow constables who valued her "calm, collected and professional manner" which could calm potentially dangerous situations.
Nicola Hughes, 23, died from her wounds despite the efforts of paramedics to save her at the scene. Hughes had three years' service with the force. The "bubbly chatterbox" loved to socialise and had a love of life. Fahy said she was always smiling - "even after a night shift when everyone else was a bit grumpy. She was a good listener and a lovely friend and a great bobby".