Nathan Delaney had endured a tough life. Losing his parents at 6 years of age. He found his way when he became a United States Soldier in the Armed Forces with Navy SEALs, 4 years later he transferred to the Naval Reserves he desired for more action and joined the Chicago Fire Department. There he joined the brave men and women of 51. apps from all One Chicago Characters including Jimmy Borelli who never left in Season 5 and Gabby Dawson who never left in Season 6