Hundreds of shoppers flocked to a Tesco as it opened early for NHS workers because of the coronavirus outbreak.
Supermarkets have announced priority shopping to give health workers easier access to restocked shelves.
But at Tesco Extra in Dudley, hundreds of people queued before 09:00 GMT on Sunday with one describing the scenes as "mob rule".
Tesco said it would "take learnings" from the opening and continue to offer priority shopping times to NHS workers.
Jan D'Arcy, who works in the breast screening department at Russells Hall Hospital in Dudley, said: "This was a slot that was given for NHS staff, nobody respected that. It was mob rule.
"I think they just let anybody through the door, I think that was the safest thing to do to prevent any kind of disturbance."
Mrs D'Arcy said there was no social distancing and while the atmosphere was not aggressive, it was "every man for themselves".
"I don't think they [Tesco] anticipated what was going to happen," she added.
"If they did it was very poor organisation. I think people are not thinking right. They are not thinking rationally.
"It made me feel really sad and on the way back in the car I did shed a tear."
A Tesco spokesperson said: "We are trying hard to do the right thing and while feedback on this morning has been positive, we also recognise that many stores were still very busy.
"We need customers to help us by giving NHS workers priority during this hour and so we ask all other customers to shop during the usual Sunday opening hours."
Follow BBC West Midlands on Facebook, on Twitter, and sign up for local news updates direct to your phone.