A fire is in a building. Firefighters go to the building. They see smoke.
The firefighters stop the fire. They find a person inside. The person is hurt.
The police look at the fire. They want to know why. They want to know who the person is.
The police do not know why. It is a question. A doctor will look at the person.
The police ask people. Did you see something? They want to find the truth.