Eye-witnesses said the crane’s load-bearing straps snapped showering timber and glass over Great Junction Street in Leith last Friday.
The load fell onto a Mercedes car which was crushed but the driver escaped relatively unhurt.
One local shopkeeper told The Scotsman: “It had landed on the car, he was very lucky not to be killed.
“I think it was down to the make of the car that it didn’t collapse on him. He was shocked and scared but said he was OK.
“All the glass had smashed and gone through onto the seats. I believe one of the builders was hurt as well. I don’t know how it happened.”
Fire services said injuries to the trio – aged 46, 33, and 32 – were not serious. One was treated for minor head injuries while the others were treated for shock.
Further injury was avoided because most of the material fell within the site where main contractor CCG is builing new homes for the Port of Leith Housing Association.
A Police Scotland spokesman said: “We received a call at around 10.40am involving a crane that dropped its load, and some debris which struck a vehicle.
“The driver was taken to the Edinburgh Royal Infirmary for shock.
“A construction worker was also taken to hospital for minor injuries. The road was closed, but it reopened just before 1pm.”