[X]Confined to or trapped in a low-oxygen environment, occurrence at school, other institution and public administrative area
[x]confined to or trapped in a low-oxygen environment, occurrence at school, other institution and public administrative area
[X]Confin to/trap in low-oxyg envir sch oth ins/pub adm area
[x]confin to/trap in low-oxyg envir sch oth ins/pub adm area