plumbing nightmare scenario - what would you do?

I’d first get diners and staff out of the flooded area and keep them away from any electrical equipment or standing water near it. If the leak clearly comes from an accessible shutoff and someone can reach it safely, shutting it off may limit damage; I wouldn’t hunt for an unfamiliar valve or try a repair from a video. I’d call an emergency commercial plumber while staff manage the affected area and wait for qualified help.

Alongside calling an emergency commercial plumber, I’d ask the regular plumber for an after-hours backup or trusted referral, even if they can’t come themselves. That gives the owner another lead without delaying the call for help; staff can keep the affected area closed while those calls are underway.

I’d use a search or app to find an emergency commercial plumber, not to diagnose an active restaurant flood from a video. A clip can’t show what’s behind the wall or whether the same-looking fixture is connected differently; following the wrong repair steps could waste time or worsen the damage. Online instructions make more sense for a known, non-urgent repair than for guessing at a live commercial failure.

The referral call is more useful if the owner can give a brief, factual handoff: where the water is appearing, whether it still seems to be flowing, and which areas are affected. Stick to what staff can see safely, and mention any shutoff already used; don’t send someone searching through the flooded area for more details before calling.

There usually isn’t one universal emergency-plumbing hotline; contact options depend on the area. For a restaurant flood, I’d look for a local 24-hour commercial plumber rather than rely on a general hotline. A water or sewer utility’s emergency number may be relevant if the problem appears to involve its public system, but it may not dispatch someone for a leak inside the building.

Your advice to keep people out of the flooded area makes sense. In this scenario, would you keep unaffected parts of the restaurant open only if staff can clearly separate them from the water and any electrical hazard, or close more broadly until the plumber assesses it?

I’d keep an unaffected section open only if staff can clearly keep customers away from the water and any possible electrical hazard, with a reliable boundary between areas. If that separation is uncertain - or the hazard could extend beyond the visible water - I’d close more broadly rather than make staff judge it during service, and wait for the plumber’s assessment before reopening.