FERGUSON, Mo. — Police and protesters clashed briefly in Ferguson just hours after the St. Louis suburb's police chief issued an apology to the family of Michael Brown, a black 18-year-old who was fatally shot by a white police officer last month.

Ferguson Police Chief Tom Jackson appeared outside the police department in civilian clothes late Thursday to assure protesters there would be changes in the wake of Brown's killing.

“All those things that are causing mistrust are being evaluated and we are going to be making changes,” Jackson said.

The police chief started to march with protesters around 11 p.m. Soon after, a scuffle broke out about 20 feet behind the chief and one protester was arrested. At least three other protesters were arrested after another confrontation.

CHICAGO — A fire at a suburban Chicago air traffic control facility this morning halted all flights in and out of the city's two airports, threatening to send delays and cancellations rippling around the nation's air travel network.It was the second time since May a problem at one of the Chicago area's major control facilities prompted a ground stop at O'Hare and Midway international airports.The fire led to the evacuation of the Chicago Air Route Traffic Control Center in Aurora, Federal Aviation Administration spokesman Elizabeth Cory said.One injury was reported, Cory said, without providing details. Management of the region's air space was transferred to other facilities, but it was unclear how long the stoppage would last.