A 65-year-old man was left trapped down a manhole for 45 minutes while shoppers ignored his cries for help.
Clive Collins was opening his car boot in a car park in Boscombe, Dorset, when the manhole cover tipped, and he slipped down the 5ft (1.5m) hole.
He said: "Probably about 15, 20 people walked by. The more I called out, the less they seemed to notice me."
Despite suffering broken ribs he managed to get his mobile phone out of his pocket and call 999 himself.
Mr Collins told the BBC: "What surprised me is that they didn't make eye contact.
"A woman actually parked along side my camper and put the hood up on her car.
"I said 'can you please call me an ambulance' and she refused to acknowledge the fact that I was there."
Mr Collins said one shopper did acknowledge him but did nothing to help.
"One chap looked straight at me in his car driving very slowly by and I waved. He waved back and then carried on," he said.
Mr Collins was taken to Royal Bournemouth Hospital and needed 47 stitches and treatment for two broken ribs, a chipped tooth and a strained groin.
Carly Earnshaw, spokeswoman for Bournemouth Borough Council, said: "A full investigation is being carried out as to how this happened and if any vandalism on the manhole has taken place.
"In the meantime we would like to reassure residents that the site is now secure and that we do have policies in place to maintain our car parks."