Carleton University locked down due to sound of popping balloons

The sound of popping balloons at Carleton University prompted a campus-wide lockdown on Sunday after students called 911 because they believed shots were being fired.

Students called 911 after hearing what they thought were shots being fired on Sunday evening

Ottawa police were dispatched to Carleton University on Sunday evening after students heard what they thought were shots being fired. It turned out to be the sound of popping balloons. (Jean-Sebastien Marier/CBC)

The sound of popping balloons at Carleton University prompted a campus-wide lockdown on Sunday after students called 911 because they believed shots were being fired.

The balloons were being popped on the third floor of the Tory building, according to Ottawa police.

The popping sounds led multiple people to call 911, starting at about 6:20 p.m. Some students took to social media to sound the alarm.

Responding officers and campus security personnel initiated a campus-wide lockdown while they investigated.

The lockdown was lifted after about 20 minutes when investigators determined there was no threat to public safety.