Big crowds emerge on the streets, despite officials repeatedly asking people not to come see the demolition.

Thundering explosions toppled two cranes that loomed precariously for days over a partially collapsed hotel in New Orleans, blasts city officials hailed as a success as they said efforts would now focus on retrieving two bodies inside the ruined building.

More than a week ago the Hard Rock Hotel that was under construction near the historic French Quarter partially collapsed. Three workers died when several floors of the multi-storey building pancaked. Only one body has been removed so far.

The blasts on Sunday sent up massive clouds of dust and one crane crashing to the street while the second fell in a way that left much of it resting atop the hotel. Officials said it was “stable” and could be removed piecemeal.

“We know that we are safer now than we have been in the past eight days,” said Mayor LaToya Cantrell, speaking at a news conference after the explosions roared through the city’s downtown.

The cranes – one about 82 metres (270 feet) high, the other 91 metres (300 feet) – weighed thousands of tonnes and were badly damaged in the collapse. They had been tilting dangerously and officials feared they would come down on their own, possibly smashing into nearby buildings or severely damaging underground gas and electric lines.

Throngs of onlookers

Once the dust cleared on Sunday, it appeared none of those worst-case scenarios came to pass. The mayor said three windows at the historic Saenger Theatre across the street were damaged. A sewer line was damaged as well but padding designed to protect the gas and electric lines – a major concern – worked as expected.

“I do not think it could have gone much better,” said Fire Chief Tim McConnell.

Officials repeatedly asked people not to come see the explosions but there were throngs of onlookers on the streets. Some brought earplugs and masks to protect against the dust. Others had to be removed from nearby rooftops where they gathered to gawk as police did their final checks.

Loud alarms sounded and a voice on the police radio said repeatedly “Prepare for detonation!” before explosions set off a thunderous boom. Flashes from the blasts could be seen as the explosives went off.

After the bodies are removed, the building will be demolished.

The cause of the collapse remains unknown. The Occupational Health and Safety Administration and police are investigating.