The underground explosion, and resulting fire, and smoke was a caused by electrical problems with the underground cables in the area.
During the evacuation, outside of police headquarters, an officer was shot. It appears he was shot in the left hand, and thigh. It is unknown if it was a regular officer, or reserve officer. He was rushed to the hospital in a police car, and is in temporary serious condition, but expected to recover. It's unknown how he was shot, and/or if it was an accidental shooting, possibly self inflicted.