PITTSBURGH — Pittsburgh's Municipal Courts building was briefly evacuated after workers were apparently sickened by exhaust fumes.

Emergency workers say four people were treated for high carbon monoxide levels this morning. At least two had to be transported to hospitals after being overcome by exhaust fumes of some kind.

The building reopened a short time later.

City 911 dispatchers say an idling diesel truck may have been the culprit. They say similar incidents have happened in the past.