One person was killed and three others are missing after a Hard Rock Hotel under construction in New Orleans collapsed Saturday morning.

The city's fire department received a call about the collapse just after 9 a.m. Police and emergency medical services also responded.

One person was pronounced dead at the site, a fire official said during a news conference.

“It’s a very dangerous situation,” Fire Superintendent Timothy McConnell said, adding that the building is “unstable,” and another collapse is possible.

Eighteen people were taken to the hospital in stable condition. One person who was injured refused medical treatment.

The upper floors of the building began to fall on top of each other before one side of the building fell to the ground below, The Associated Press reported.

"This remains a very fluid and very dangerous situation, and every few minutes something is falling off of this building," Louisiana Gov. John Bel Edwards said.

The city's fire department posted photos on Twitter showing the roof and several floors partially destroyed with a large pile of debris scattered on the street below.