One person is dead and others are still missing after part of the Hard Rock hotel under construction in downtown New Orleans collapsed Saturday morning with what witnesses described as a rumble and giant cloud of dust. Multiple injuries have been reported, authorities said.

[UPDATE, 7 p.m.: The search for two people still missing in the wreckage of the partially collapsed hotel building has been haltered for the night, officials said. Read more here.]

Authorities said 18 people had been transported to area hospitals after a portion of the upper floors of the building at North Rampart and Canal Streets collapsed around 9:10 a.m. They were reported in stable condition. There are no reports of anyone on the street being injured.

With tears in her eyes, Nova Espinoza stood behind yellow tape on Elk Place and Canal Street and looked at the collapsed Hard Rock Hotel construction site.

“I don’t know where my husband is,” she said.

Anthony Magrette of King Company was on the site during the collapse. He has not been accounted for, Espinoza said.

“Nobody from his company has seen him. They can’t find where he is.”

Another woman, Betty Kellar, awaited updates on her cousin, Quania Wimberly, who she said was also unaccounted for.

“We’re still waiting, but we still have hope,” Keller siad.

Wimberly was a construction worker on the site, but Kellar wasn't sure what company he works for.

In an 11:20 a.m. news conference near the scene, New Orleans Fire Department Superintendent Tim McConnell said the upper six to eight floors of the structure collapsed and that the building remains very unstable.

Authorities were evacuating buildings in a square roughly bounded by Bienville Street, Basin Street, Canal Street and Burgundy. Saturday's performances of Wicker at the Saenger Theatre, which is across North Rampart from the hotel were cancelled.

"The building is unstable, so a collapse is still possible," McConnell told reporters.

One worker said about 45 people were working inside the building.

“I was on the 18th floor when it happened," he said. "We ran to the center of the building to escape.”

Teams planned to use drones and dogs to aid in the search for missing workers.

In videos circulating on social media, parts of the building can be seen falling onto North Rampart as people on the street flee in terror.

Witnesses described a surreal scene of destruction.

"It sounded like a -- I don't know how to describe it -- like a building coming down," said Matt Worges, who saw the collapse from the nearby Tidewater Building.

"It was a deep, rumbling sound," he said. "Like an airplane maybe. It drew my head immediately."

+29 Watch: Hard Rock Hotel New Orleans construction site collapse captured on video An eyewitness captured on video the moment the under-construction Hard Rock Hotel in downtown New Orleans collapsed on Saturday morning.

Worges, studying in a 23rd floor classroom at the Tulane School of Public Health, looked out of the window to see a portion of the building in mid-collapse.

"It looked like the concrete just slid from the top all the way down to the street," Worges said. "The concrete just started to slide down the side."

Worges said in the aftermath he began to see people moving around as the multitude of emergency vehicles began to arrive.

Can't see video below? Click here.

"One guy -- I don't know how he was spared -- there was rubble all around him," he said. But, Worges added, that man was able to climb on his own down a fire truck ladder to the street below.

Another witness, Keith Director, was driving on Rampart when he heard a loud "bang," that drew his attention to the building. He said a huge crane swing and what appeared the whole front of the building collapse.

"It saw two guys on about the 10th story just hanging on," Director said. The crane, he added, "was just sort of dangling there."

Felicia Jones, who was in her home nearby at Treme and Iberville streets, said it felt like an earthquake.

"My whole couch moved," she said.

It's unclear what caused the collapse.

Witnesses at the Ruby Slipper saw a cloud of smoke consume the area, a witness said. People who were outside ran into the restaurant.

Plans for the 18-story, mixed use development were unveiled in February 2018. Led by Florida-based Hard Rock International, the development called for 350 hotel rooms, a pool and assorted meeting rooms on the site of the former Woolworth Department Store. The development was to also have condos, ranging from 650- to 2,300-square-feet.

In a statement released Saturday, Hard Rock International said the contractor on the project, Citadel Builders LLC, was hired by the project's owner, Kailas Companies, and that Hard Rock "has had no involvement in the construction of the project."

"We want to extend our deepest sympathies to victims of this tragic accident and to their loved ones and friends," said a spokesman for the company in a prepared statement.

Metairie-based Citadel Builders is the general contractor. On its website, the company says the project's budget is $85 million.

The project has been in the works for the better part of the last decade, and has stirred controversy at times.

In 2011, the City Council voted to give then-developer Praveen Kailas zoning waivers to allow the project to proceed, the most controversial of which was an allowance for extra height. The zoning at the time would have limited the building's height to 70 feet.

After the approvals, the project was slow to launch. Kailas was sentenced to two and a half years in prison in late 2013 for systematically overbilling the Road Home program.

Stewardship of the 1031 Canal project was passed to another member of the Kailas family. The old Woolworth's building was finally demolished in 2015, but it wasn't until 2018 that the Kailas Cos. announced a deal with Hard Rock.

Plans for the hotel and condos were substantially similar to those the council approved back in 2011.

This is a developing story. Check back for more details.