What is Maniac doing when the older gentleman approaches him?

On a hot August day, Maniac Magee was with his friends in the East End trying to cool off.  Someone had "wrench[ed] off the cap" of the fire hydrant, and water was spraying everywhere.  Maniac and other kids were dancing and playing in the mighty flow of the water from the hydrant, trying to cool off. Maniac would step in front of the strong stream and let it push him.  Suddenly, Maniac heard a voice.  He saw an older man approaching him.  This man was so old that his "white hair curled around his ears."  This man called Maniac "whitey" and told him to leave the East End.  The man told Maniac to go back to live with people who were like him.  In the East End, almost everyone was black. In the West End, almost everyone was white.  This man wanted Maniac to go move to the West End.