Chicago Fire Department Deputy Commissioner John McNicholas resigned Wednesday, according to a statement from the Department.
"McNicholas was involved in a traffic accident on April 20 near Lakeshore Drive and North Avenue in a department vehicle," the statement reads. "The Deputy Commissioner has been fully cooperative with the Internal Affairs Division of the department. The investigation has thus far found that McNicholas was operating his city vehicle outside of department policy."
McNicholas submitted his resignation Wednesday afternoon, effective immediately, authorities confirmed. The investigation is ongoing.