Witness was at work during the event and was called outside at the time of the observation. A co-worked called out "Guys come here, UFO!" Four witnesses observed a bright red orb moving slowly from southwest to north as if skirting the edge of the city. The object was at a 45º angle to the witnesses, size and distance to the object are unknown and could not be speculated. The flight path of the object was erratic at times during the observation and it appeared to "wobble". Object then became smaller and changed colour from red to orange. As the object changed colour to orange it began to speed up as if it was travelling as fast as a jet. During the acceleration object changed from orange to a yellowish/white colour. The object was travelling so fast at this time that it disappeared from sight. One of the witnesses was able to take 4 photographs of the object.The location of the event is north of a major international airpot but no other aircraft or helicopters were seen or heard in the sky at the time.During the event the witnesses expressed a feeeling of unease similar to the "heebee jeebies". They were all very excited and had the chills. No electronic devices reacted unusually either before, during or after the event. There were no sounds from the object or animals nearby. No unusual odors were detected during the event. The event lasted approximately 30 secs from the time the witnesses first saw the orb to when it disappeared to the north.The witness is a trained professional with good eye sight and health. Health and eyesight of the witness were not affected by the observation of the object.None of the witnesses had consumed any alcohol or drugs at the time.The witness appears to be credible. Only a few minor details changed from the original report to my followup interview.