1-15-07 Day classes at Grayson County College were cancelled Thursday morning because of a water main break. Officials with the City of Denison say the break happened around midnight Wednesday night. Crews found the damage at 2:00 am and have been working on it since. Officials say they hope to get the problem fixed by 1:00 pm and classes are scheduled to resume then. The cause of the break is not yet known, but officials say the recent low temperatures could have led to the break.