Black Triangle Sighting in Chicago, Illinois on July 4th 2015 – Over 20 objects in the sky during fireworks moving single file then disappeared

Around 930-10pm on July 4th while waiting to watch local fireworks noticed 20 or more white/yellow lights in the sky. All in single file line in the sky they then moved in a straight line and increased speed and then disappeared into the sky. They made no noise and it was a strange