be on alert

The school asked everyone on campus to remain indoors and be on alert.

When an airline or a manufacturer figures in a headline-generating episode, the media and the public tend to be on alert for other problems involving the company, even those that have little to do with the company or that might not even be significant enough to attract much attention from safety agencies.

“We had to be on alert and I had to formulate the response,” Petit said.

The center advised those in the area to be on alert and “watch for cracking” before traversing through avalanche terrain.

City will have to be on alert for a player who is not afraid to put them on the back foot with intelligent dribbling and movement.