A restaurant manager was tricked into breaking all the windows of his business as the result of a malicious prank phone call, according to police.

Investigators said the incident happened at a Wendy's restaurant in Phoenix on Jan. 30. The unknown caller masqueraded as a member of the local fire department, telling the manager they needed to conduct a diagnostic test on the restaurant's fire system.

The manager followed the caller's instructions and activated the building’s fire suppression system. After activating the system, the manager was informed the action caused a gas leak and that all occupants needed to leave the restaurant.

Once everyone was outside, the manager was instructed to break all of the windows to prevent an explosion.

According to police, the Wendy’s employees broke all of the windows and waited for the fire department to respond.

Fire department and gas company officials later arrived at the restaurant and determined the call had been a hoax. A police report was taken on the scene.