This morning at approximately 8:45 a distinct gas odor was detected.  We evacuated all students and staff within two minutes to alternative sites.  The gas company responded to investigate.  Ultimately a small leak was detected in the boiler room, a sensor valve on the gas dryer used to wash mop and towels was the culprit.  We cleared the odor from the building and the all clear was giving to return at 9:35.  The students/staff did an excellent job of evacuating and remaining calm.  In addition, the teachers/staff continued teaching with little instruction time lost.