With increasing violence and a state of emergency in Baltimore, the American Heart Association is cancelling the 2015 QCOR conference that was scheduled in the city this week.

“Your safety and well-being are our highest concerns,” read the notice sent to attendees late Monday night soon after the city’s mayor activated the National Guard and imposed a curfew.

“After speaking with local authorities, hotel management and the Convention and Visitors Bureau we have decided to cancel the 2015 QCOR conference due to the potential for violence,” the notice said.

The AHA was considering how to handle requests for refunds of registration fees.

QCOR was one of many events being cancelled on Monday as the city was rocked by protests and riots following the death of 25-year-old Freddie Gray, who has become the nation’s latest symbol of the debate over police use of force.

The AHA office in Baltimore is in the heart of downtown. While the violence had not reached that part of the city, the organization’s staff will work from home for the near future to assure their safety.

“As you know, our staff and volunteers are our greatest resources.  They are what drive our life-saving mission.  So we take employee and volunteer safety very seriously,” said AHA CEO Nancy Brown.