at fault

Idioms  

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.

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Example Sentences

In this case, an Old World hantavirus was at fault, not the Andes strain that’s responsible for the outbreak on the cruise ship.

From MarketWatch • May 8, 2026

The minister called Mary's experience "totally shocking" and couldn't imagine being in her position where you've asked for help "and the response has been that you're at fault".

From BBC • Mar. 18, 2026

The report suggested possible causes for the premature fuze detonation but determined that military personnel were not at fault.

From Los Angeles Times • Mar. 16, 2026

But sources told the New York Times that “outdated targeting data” may have been the cause and the U.S. was at fault.

From Salon • Mar. 14, 2026

The dream was at fault, for the treadmill mood of it had lingered, making him question Nye’s assertions—in a sense, disbelieve them.

From "In Cold Blood" by Truman Capote