Excerpts from abc7chicago.com:

Joshua and Jacob Bucio, sons of Chicago Fire Department Diver Juan Bucio delivered the game ball at the White Sox game Friday night.

Bucio died in late May while trying to rescue a missing boater who had gone overboard on the South Branch of the Chicago River. 

He is survived by his sons Joshua, 10, and Jacob, 7. The Chicago White Sox invited them onto the field Friday night before their game against the Oakland Athletics.