"Two of the people injured by the tank filed a lawsuit this month against the Brewster's owners and the condominium association."
In my experience in the US, forensic investigations are usually performed on behalf of insurance companies, attorneys, and property owners, in that order. Building departments are completely unpredictable when it comes to these types of matters, from being very proactive to putting their heads in the sand. Just trying to reach the right person to talk to when you are trying to report a dangerous condition can be a huge task.
The plaintiff's attorney for the injured people will hire a forensic engineer, as will the property owner's insurance company, and maybe even a third for the condo association if they are named in the lawsuit.
And if I was that structural engineer, I would call my E and O insurance company.
The cops should look to see if Wile E Coyote has a good alibi.