Two families came together as one after a deadly fire took the lives of a teenage hero and the toddler he tried to save.

Family members say 19-year-old Lucas Silverio ran back into a 16-story building to try to save the 3-year-old, who he was alone inside crying. Officials say both Silverio and Yasleen McDonald suffered burns to 80 percent of their bodies.

MORE: Teen dies from injuries sustained trying to save child in fire Sunday 

The fatal fire forged together the two families, who met for the first time at a funeral home Thursday as they mourned their losses.

"19 years old ... what 19-year-old would actually click in his heart to go save a 3-year-old?" says one family member.

The FDNY says they are still investigating the cause of the fire.