A Hidden Danger That Could Have Silently Killed!

On this large older commercial building the roof had been replaced about five years ago. We inspected the roof and other than minor issues it was very functional.
There was a big stainless steel flue pipe up the side of the building for the 250,000 BTU boiler that supplied heat to the building. Four hours later in the basement we observed a second boiler that had been abandoned as we continued the inspection, in another area there was a row of water heaters with only one currently in use and all connected to the same chimney as the abandoned boiler.
Did we remember a chimney on the upper roof? No, checked our notes and there was no chimney.
Getting our ladder and climbing back up on the roof we confirmed that the only chimney had been knocked down, removed, capped off and roofed over.
Someone had forgotten that the water heaters located in the unused part of the basement were still in use and connected to the same chimney as the abandoned boiler. All the carbon monoxide from that water heater flue pipe was venting into the building and could have had serious consequences for the large gatherings of people there every week.
Inspections often save lives and this one thankfully did.