It was my fault.

Meaning

Taking responsibility.

Examples

• John: I'm so sorry about what happened.
• Alice: It's okay, but what happened?
• John: <b>It was my fault</b>. I should have been more careful.
• Alice: I appreciate you taking responsibility. I have to admit that I made a mistake too. But what's done is done, and we know that <b>it was my fault</b>.