train wreck

or train·wreck

[ trein-rek ]
/ ˈtrɛɪnˌrɛk /

noun

an accident in which a train or trains are severely damaged.
Slang. a person who has experienced a personal failure, disaster, etc.
Slang. a disastrous situation, occurrence, or process: His football career has been a train wreck.

British Dictionary definitions for train wreck

train wreck

noun

an incident in which a train is severely damaged
informal something or someone that has suffered ruin or calamity