a false alarm

false alarm

A benign situation initially mistaken for an emergency. Mary thought she was going into labor, but it turned out to be a false alarm. When the smoke detectors started beeping, we thought the building was on fire, but it was just a false alarm caused by faulty wiring.
See also: alarm, false

a false aˈlarm

a warning of something, especially something unpleasant or dangerous, which does not in fact happen: They thought the packet contained a bomb but it was a false alarm.
See also: alarm, false
References in periodicals archive ?
Washington, Rabi'II 26, 1439, January 13, 2018, SPA -- An alert saying a missile was headed for Hawaii was a false alarm, officials said Saturday after people in the US state were alarmed to see a warning about an imminent threat on their mobile devices, according to dpa.
FIRE crews are attending a false alarm every other day at Birmingham hospitals.
Summary: New Delhi [India], June 15 (ANI): A false alarm - reports of gunshots in the vicinity - triggered a lockdown at the Travis Air Base in California on Wednesday.
This resulted in fire engines being mobilised on blue lights 18,000 times - almost ten a day - to what turned out to be a false alarm.
The official definition of a false alarm is "a fire signal resulting from a cause other than fire".
Whether you have an installation or maintenance issue, a false alarm is a warning that your system has been compromised.
Andy Talbot, shopping centre manager, confirmed it was a false alarm, saying: "We estimate about 2,000 people were evacuated from the shops and car park.
JohnDuffy, FBUScotlandregional secretary, said: "You don't know it is a false alarm until you get there.
My wife will never forget sitting on the front steps of our daughter's home as Seattle police walked up the sidewalk because she set off a false alarm.
Firefighters were called to the Dow Corning chemical plant, in Cardiff Road, Barry, just after 5pm yesterday but the emergency was called off just after 6pm when it was found to be a false alarm.
On the evening of 6 October, an alarm for radioactivity was sounded for a parcel, but one and a half hours later it had been clarified that it was a false alarm.
What constitutes a false alarm, or put another way, what is the definition of an avoidable alarm as opposed to an unavoidable or excusable one?
Where one desires maximum available sensitivity, the one a day rate is good; in other situations desiring assurance that an alarm is real, a false alarm rate of one per year may be acceptable.