US: Woman Dies And Nine Others Taken To Hospital After Breathing In Toxic Fumes At McDonald's | UK News | Sky News
"Reports say cleaning products may be to blame for the fumes"
I have drawn your attention before to toxic cleaning products.
After websearching for possible causes of this toxic fumes incident, I suspect that it a lethal combination of bleach and urine.
I welcome comments from persons with chemistry qualifications.
Guide to Less Toxic Products