Condolences for sure. Do you happen to know the size of their place by chance? CO becomes deadly at about 400 PPM or 0.04%. Doing the calculations I can't for the life of me figure out how a small laser cutter could produce enough CO under any condition to become deadly. Even with the smallest of places, lets say 24x20x7 studio, that's 3,360 cubic feet of air & at 0.0807 pounds per cubic feet of air, that means roughly 271 pounds of air. To become toxic, that would mean the laser cutter would need to output 0.1084 pounds of CO or roughly 1.7 ounces of CO in that area and then not get dissipated through air leaks, opening and closing the exterior door, etc. That seems exceedingly high given a laser is going to cut very little actual material and even getting to the point where it has cut 1.7 ounces of material, let alone produced 1.7 ounces of CO would seem to me to take weeks, months, or years.
Based on public records, appears the building is a fourplex and the total floor space for the building is 3328 square feet; as such, my guess is the their unit was 832 SQFT. Room height based on exterior photos roughly appears to be 8-10 ft.
