COPENHAGEN, Denmark >> All five people inside a construction site elevator that crashed to the ground in Stockholm have died, a Swedish prosecutor said today.

Authorities had previously only reported that the occupants were seriously injured when the elevator plummeted 66 feet in Sundbyberg, a Stockholm suburb, on Monday. It is still unclear what caused the accident. Construction at the site has been stopped.

Gunnar Jonasson, the senior prosecutor in charge, said there is an ongoing preliminary investigation, including by the National Accident Commission, on suspicion of “work environment violations causing the death of another.”

“This is a serious incident that we are now investigating,” Jonasson said. He added that authorities are working on ensuring the identity of the deceased and contact is being made with relatives.

The prosecutor said nothing more about how or when the victims died in the brief statement.

A spokesman for the company that manufactured the elevator told the Aftonbladet tabloid on Monday that that type has been used around the world for more than 20 years, and the company had never been involved in such an incident before.

Andersson Company Byggnads, the construction company that runs the site of the accident, said that all those who died were employed by subcontractors, adding in a statement that “as the main contractor, we have a primary responsibility for safety at the workplace.”

Swedish broadcaster TV4 said that all construction elevators in Stockholm were stopped following the fatal accident and quoted Tomas Kullberg, the local head of the Swedish Construction Workers’ Union.

Johan Lindholm, the national head of the same union, called 2023 “the darkest year in a very long time.”

“Fatalities and accidents both can and must be prevented,” Lindholm said in a statement.