Part of the city centre was sealed off this afternoon after the tragedy, which happened as shoppers went about their business on Dudley Street.
The woman, aged 29, had initially been said to have been sitting outside the coffee shop enjoying a drink with friends.
But this evening, West Midlands Police said she had been walking past when she was struck by 'wooden debris'. Witnesses described it as being 'the size of a coffee table'.
UPDATE: Dead woman named as Wolverhampton University worker Tahnie Martin
UPDATE: Investigations continue as tributes are left to woman killed in city centre
West Midlands Police spokesman Deborah Edmonds said this evening: "Sadly nothing could be done to save her and she was pronounced dead at the scene.
"Officers are now working with emergency service colleagues and Wolverhampton Council to establish how this tragic incident happened.
"The area remains cordoned off while investigations are ongoing.
"The lady's family have been informed and are being supported at this tragic time."
There were fifteen 999 calls at 11.43am made to the emergency services in the wake of the incident.
Crews from West Midlands Fire Service together with paramedics and police are at the scene in Dudley Street.
West Midlands Ambulance Service spokesman Murray MacGregor said: "On arrival, crews found a woman who had suffered very serious head injuries.
"Sadly, it quickly became apparent that there was nothing that could be done to save her and she was confirmed dead at the scene."
Two ambulances, a paramedic area support officer and the critical care paramedics from the Midlands Air Ambulance in Staffordshire, who responded on a rapid response vehicle, were sent to the scene.
Wolverhampton City Council said: "An awful tragedy and our thoughts with all involved."
A Starbucks spokesman told the Express & Star: "We are shocked and saddened by this terrible incident. We are supporting the police with their investigation and our store will remain closed until further notice."
Express & Star reporter Alex Ross provided this update from the scene
Rebecca Davis, a 40-year-old teacher from Wolverhampton, said she saw a woman aged "between 20 and 30" receiving CPR.
She said the woman appeared to have been hit by something resembling a piece of roof which had fallen off a building nearby, but was unsure where it had come from.
"I think the wind broke it and caused it to fall. I don't know if it was hit by something else or just the wind did it," she said.
"I don't think anyone else was hurt. It was a big piece about the size of a coffee table but I think it just hit her," Mrs Davis said.
John Jackson, 72, from Fallings Park, was in the city shopping and witnessed the immediate aftermath of the incident.
He said: "It was utter chaos.
"It is hard to believe the young woman has died.
"They said the weather would be terrible but this was unimaginable."
Gavin Hunt, 35, from Dudley, was in Wolverhampton with work at the time.
He said: "I was driving over from Dudley when I first heard there had been an incident.
"It is shocking. It is really tragic.
"Obviously I have no idea what family she might have but my thoughts are with them at this time.
"It makes you wonder 'that could have been me out walking' and makes you realise something like this can happen."
Read a round up of today's events here
Councillor Barry Findlay, Mayor of Wolverhampton, said: "I am deeply shocked by this terrible tragedy.
"A woman has lost her life right in the heart of our city centre and my thoughts and prayers go out to her family, friends and all involved.
"People will have no doubt witnessed the incident and its aftermath and it must have been deeply distressing.
"I know the emergency services were quickly on the scene but it appears there was nothing they could do to save her.
"Investigations will obviously now take place to establish exactly what happened."