A University of Michigan sorority that popped balloons that sparked a false active shooter alarm earlier this month apologized in an open letter to the campus community.

In the letter, published Sunday on the Michigan Daily's website, the University of Michigan Chapter of Alpha Kappa Delta Phi said there was no malicious intent in the move.

"Last week, a group of our members had planned a bonding event that involved team-building activities, including one that involved popping balloons that set off the false shooter alert," the letter said. "We are truly sorry to everyone who feared for their lives and had to experience the traumatic events of that day, especially to our fellow Muslim students and all those who were present at the New Zealand Mosques Solidarity Vigil. It is unacceptable to merely pass off our actions as a poorly timed coincidence. To do so would be to ignore the politically charged atmosphere that day and the many serious events on campus that preceded the false alarm …

"We have used this past week to not only process our feelings of guilt and disbelief, but to also reflect on our mistakes and take responsibility for our actions by reaching out to members of our immediate communities …

"While our words cannot undo the trauma that was experienced that day, we will use Saturday’s events as a way to further educate ourselves more about social justice and to empower and uplift our fellow Muslim community and communities of color."

More:False active shooter reports spark high tension at University of Michigan

The balloons popped in the late afternoon of March 16, just as a vigil was going on the Diag for those killed in a shooting at two New Zealand mosque.

Dozens of people called 911 to report shots being fired and U-M locked down the main part of campus while police from nearly every agency in Washtenaw County went room-by-room, searching a large classroom complex.

Monika Paliwoda was working on a design project in the Fishbowl of U-M's Mason Hall on Saturday afternoon when the people next to her alerted her to reports of an active shooter in the building.

She and five others headed for a classroom from the Fishbowl, a giant glass-encased room full of computers. They slammed the door shut and hid in a corner for an hour.

"We kept hearing random doors open," she said minutes after leaving the building. "I wasn't sure who was going to open our door. I thought I was going to have a heart attack each time I heard a door open. We finally heard police down the hall yelling, 'Police' as they came in."

Contact David Jesse: 313-222-8851 or djesse@freepress.com. Follow him on Twitter: @reporterdavidj