A beloved mum described as “kind, caring and fun” died after falling ill during her working shift at The Range.
Other members of staff attempted to help the worker, named locally as Tracy, but despite the best efforts of emergency services and colleagues she died a short time later.
For a brief period police stopped shoppers from entering the car park at the Croft Retail Park store using barriers.
Tributes have poured in for the mum and nan, who has been described as a "loving" person, reports the Liverpool Echo.
A GoFundMe page was launched in the wake of the tragedy by family friend Jessica Gregson which has so far raised more than £100.
She said: “For those who are not aware, Tracy very sadly passed away unexpectedly while at work and unfortunately despite efforts of staff/ work colleagues and the emergency services nothing could be done for her.
"This has come as a huge shock to all Tracy's family, friends and work colleagues and has truly been the most devastating time for everyone. Tracy was such a kind, caring, fun, loving and very much loved lady by everyone.
"Tracy will be dearly missed by not only her husband, children, siblings, grandchildren, all family but also her friends and work colleagues and will certainly never be forgotten."
On Facebook, Ria Cairns said: "So sad, I was there, thinking of the family and friends also the staff and the lady who was helping sending hugs."
Lesley Tripp addeed: "So sad. Thinking of their family at this tragic time."
Sammie Fardoe said: "This was so sad, I was there at the time the lady who was trying to bring her back deserves a medal.
“She didn't stop, hope she ok and all the workers and sending love to the lady's family."
A spokesman for the Range said: "We are all deeply saddened by Friday’s events.
"Our thoughts are with the family, friends and colleagues at this difficult time."