Left holding the bag

Generated image of bank robbers
To be left holding the bag means being the person who is unfairly left with the blame after others leave. It often happens when something goes wrong and one person is left to deal with the consequences.

The expression comes from an old idea in stories about thieves. One thief would run away while another person was caught still holding the bag of stolen goods, making it look like they were the only one responsible.

Everyone else quit the project when it started failing, and I was left holding the bag.