Set off alarm bells verb phrase
To cause worry due to being an indication that there is something wrong
The rising COVID-19 cases in one country should set off alarm bells about its rapid infection rate and social crisis.
As the unemployment rate continues to increase, it should set off alarm bells about the economic downturn in the near future.
The verb "set" should be conjugated according to its tense.
If you fall for someone's trick the first time then they are at fault.
Are you going to mess with me again? Fool me once, shame on you; fool me twice, shame on me.