$win.col1.w1.f1.disasters.m add command\
-label {Meltdown}\
-command "UIDisaster $win \"sim MakeMeltdown\" \"have a nuclear meltdown?\""
+ if {[sim HasAirCrash]} {
+ $win.col1.w1.f1.disasters.m add command\
+ -label {Air Crash}\
+ -command "UIDisaster $win \"sim MakeAirCrash\" \"crash an airplane?\""
+ }
$win.col1.w1.f1.disasters.m add command\
-label {Tornado}\
-command "UIDisaster $win \"sim MakeTornado\" \"spin up a tornado?\""