BISMARCK, N.D. (AP) — At least 39 North Dakota ambulance services plan to participate in a procession as part of a memorial for three people killed in an air ambulance crash in Morton County.

Kelly Dollinger, president of the North Dakota Emergency Medical Services Association, says he expects that number to grow. Dollinger says the Monday procession is also “bound to see” ambulances from other states such as Minnesota, Montana and South Dakota.

Rev. Greg Carr, lead chaplain for Crisis Care Chaplaincy, says the public service in Bismarck will give people a chance to grieve and remember those who died in the Sunday crash: pilot Todd Lasky, nurse Bonnie Cook and paramedic Chris Iverson.

Their plane crashed in a field Sunday shortly after takeoff from Bismarck. It was flying to Williston to pick up a patient.