Police found the teenager after they were alerted at 7:30pm on Sunday.

The policeman had gone off to alert the other officers at the airport.

There was no doubt the rifle fire would have alerted the Chinese at the front of the building.

An older female colleague alerted me to this fact at the start of my scientific career many years ago.

The loud sound created will alert anyone at the building or site that there is a fire so they can escape safely.

The plan fails when the General's limousine is alerted at the last second.

I don't want to risk alerting the security force at the compound.

Her touch alerted at last what she had been seeking-a guide.

In other instances, a child's truancy from school alerted officials to a problem at home.

As crew training progresses, about 30 of the 99 bombers are alerted at one time.

But you have to stay alert at all times and the pressure is always on me to be there for the sprint finishes.

Being quite alert at the sensory level, you notice this.

Rod kept his mouth shut and stayed alert at night.

Contestants were required to stay alert during the game at all times.

The older you get, the harder it may be to stay alert at the wheel as well, finds a 2007 study.

Always be alert and aware of your surroundings, especially at night.

Ah, I'm just more alert at night times you know.

We'll need to have the emergency crews on alert at all times.

Therefore we will double our lookouts, who must be alert at all times.