The fire occurred Sunday morning on the 200 block of Concord Street.
Ralph Freeman and his son, James, were killed in the blaze.
Four-year-old Jeremiah was hospitalized following the fire, but after several days succumbed to this injuries.
Family and friends gathered Monday evening to remember Ralph and James.
Pisietta Arrington, Ralph's sister, stood at the center of the crowd.
"I want my brother back so bad," Arrington said.
Candles, cards and now tears line the sidewalk.
James' mother Khadijah Comeger said, "I just want them to come back."
Residents said police and fire investigators served search warrants late Monday to check other apartment units in adjacent buildings.
"They actually went inside today to find out if there was illegal electric that was in the building," said resident Maleeka Wade.
While one resident claimed investigators found illegal wiring, it's not immediately clear what sparked the raging inferno.
Two dead, one injured following Chester fire