at fault

1. Responsible for a mistake, trouble, or failure; deserving blame. For example, At least three cars were involved in the accident, so it was hard to determine which driver was at fault, or He kept missing the target and wondered if the sight on his new rifle was at fault. In Britain this usage was formerly considered incorrect but is now acceptable; in America it has been widespread since the mid-1800s. Also see in the wrong.

Example Sentences

But the SSA wasn’t the only institution at fault.

From Salon

Onana's only outing has come in the Carabao Cup defeat at League Two Grimsby, when he was at fault for their second goal.

From BBC

A small group online defended her, arguing she may have legitimately caught the ball and instead the father was the one at fault.

From Salon

“We believe that the evidence is clear that Edison is at fault,” Essayli said.

From Los Angeles Times

In 2023, a California state jury found Tesla was not at fault in a case in which it was alleged that Autopilot had led to a death.

From BBC