wake-up call (n)

For the insurance industry, these floods were a wake-up call.
Missing the deadline served as a wake-up call for the procrastinating student.
The economic downturn was a harsh wake-up call for businesses to reassess their strategies.
The doctor's warning about unhealthy habits acted as a crucial wake-up call for the patient.
The sudden loss in the stock market was a stark wake-up call for investors to reevaluate their portfolios.