This weekend, the $85 million, 18-story Hard Rock Hotel project under construction in New Orleans, Louisiana, collapsed, killing two workers on-site and injuring 30 more people on the jobsite or in the area. Another worker is still missing four days later, and one of the bodies of the two victims has yet to be recovered.

There were 112 workers on the jobsite when the upper floors of the building collapsed.

The project is now under investigation, but the process is slow going due to debris and the risk of further collapse inside the unstable structure. Two damaged cranes on-site are still in danger of falling. On Monday, the City of New Orleans expanded the evacuation zone surrounding the site.

The investigation into the cause of the collapse won’t officially begin until search and rescue of remaining victims is complete. Video footage will be crucial for engineers in determining the cause of the collapse. Kailas Companies purchased the project site in 2007 for $3.6 million.

The project was designed by architecture firm Harry Baker Smith and Citadel Builders was the general contractor.