An 11-year-old girl and her 8-month-old brother died in a fire Wednesday night in Jersey City.

Authorities say that the girl ran upstairs in the burning home on MLK Drive to rescue the baby, but that they were unable to escape. It is an incident that has left many Jersey City residents devastated.

“Any parent can attest to the fact that hearing something so tragic breaks their heart and how difficult it is to handle,” says Jersey City Mayor Steven Fulop.

Fulop says that one of the other siblings, a 6-year-old, woke up the mother when the fire first started.

“The mother walked out – or took the 6-year-old outside the house and the door locked behind her,” Fulop says.

Police say that the 11-year-old was still inside and is believed to have ran upstairs to get her baby brother who was still sleeping in his room. Neither of them made it out because the fire became too intense.

“There was an extreme amount of heat…a lot of fire on the ground floor. It went directly up the stairs and into the hallway,” says Jersey City Fire Chief Steven McGill. “It was upwards of 1,200 degrees up there. No one would survive.”

The fire is not believed to be suspicious, but the Jersey City police and fire departments, along with the Hudson County Prosecutor’s Office, are investigating. No other injuries were reported.

The mayor says that he will soon release information on how the community can help the family.