NEW ORLEANS, Louisiana - Emergency workers in New Orleans are preparing to enter a partially collapsed building at the edge of the French Quarter in hopes of finding two people missing since part of the building came crashing down at mid-morning.

The Hard Rock Hotel was under construction when a large section of it collapsed Saturday. One person was killed at the scene. Approximately 20 others were injured. A man who had been unaccounted for turned out to have been at a local hospital. But two other people remain missing and Fire Chief Tim McConnell says rescue workers hope to find them alive.

McConnell said only part of the building is considered stable. And a 270-foot-tall crane looming over the wreckage also is unstable and in danger of collapse -- further complicating rescue efforts.

City officials and Louisiana Gov. John Bel Edwards confirmed the death.

The building was under construction at the corner of Rampart Street and Canal Street, a broad boulevard just outside the Quarter, lined with restaurants hotels and retailers. Canal, which carries six lanes of traffic divided by a wide median where streetcars roll, separates the Quarter from the city’s main business district.

WWL-TV aired and tweeted a viewer’s dramatic video of the collapse, showing upper floors falling on top of each other before one side of the building toppled to the ground.

Another video on social media was taken by someone aboard one of the city’s famous streetcars as it approached the site while the building was collapsing. It showed what looked like a metal structure — part of the building or a piece of construction equipment — tumbling to the ground and people running from the scene as clouds of dust billowed up and around the streetcar, obscuring the view like a thick fog.

Authorities say 18 people were taken to a hospital for treatment. All were considered stable.

Edwards urged people to stay away from the area, which was still considered unstable. An unsupported crane listed away from the building site. As dust settled following the morning collapse, twisted metal, concrete pilings and other wreckage covered part of Rampart Street.

“It was a deep rumbling sound,” Matt Worges, who saw the collapse from a nearby building, told The Times-Picayune/The New Orleans Advocate. “Like an airplane maybe. It drew my head immediately.”