break the glass

Translations
сломать стекло
In case of emergency, break the glass to access the alarm.
В случае чрезвычайной ситуации сломайте стекло, чтобы получить доступ к сигнализации.
Definitions
To 'break the glass' means to take emergency action or use a last-resort solution, often in a situation where normal procedures have failed or are insufficient. The phrase originates from emergency equipment (like fire alarms or extinguishers) that are accessed by breaking a glass panel.