colossal failure

• disasterSudden ruinous event
• catastropheDevastating, large-scale misfortune
• fiascoHumiliating public failure
• debacleSudden, complete failure
• train wreckUtter chaotic disaster

meltdown · crash · flop · bust · spectacular · epic · humiliating · devastating · ruin · collapse · implosion · wreckage · blunder · Titanic · Hindenburg · embarrassment · shambles · dumpster fire