Construction work on Citadel’s new headquarters in Miami has been paused following an accident on the site last week, the Wall Street Journal reported.

The collapse of a rig on Monday prompted county authorities to issue a stop-work order pending an investigation, according to the newspaper, which cited a local building official. It’s unclear how long the stoppage will last or what caused the accident, the WSJ wrote on Sunday, adding that such probes can take up to six months.