The Summit Elementary School, closed for two days by a natural gas leak, was declared "safe and secure" on Wednesday.

Assistant Superintendent Chad Downs said some 900 students evacuated Monday morning returned to school Thursday.Mountain Fuel Supply Co. crews were summoned Monday morning when students and teachers detected an odor of gas in the building.

Milton Carlisle, manager of distribution for Mountain Fuel, blamed the frost for breaking threads in a pipe near the southwest corner of the school. He said his crew completed repairs on the pipe late Monday afternoon.

But he said "so much gas was saturated into the ground, the school had to be closed Tuesday because it was coming back into the building.

Downs said all of the cleanup work was completed Wednesday and the furnaces were turned back on.