A Brooklyn mother was charged Saturday with endangering the lives of her two sons during a Friday apartment fire, as the firefighters who rescued the boys shared details about their efforts.

Milagros Perez was arrested and charged with two counts of endangering the welfare of a child, after two of her three children needed to be rescued Friday night from their burning East New York apartment.

Authorities say Perez allegedly left her four-year-son Ezekial and two-year-old son Renaldo alone in the apartment for 25 minutes.

Lieutenant Bill Croak and Jim McNulty of Engine 257, Ladder 170 in Canarsie then entered the flaming apartment to search for the two boys. With visibility close to zero, the firefighters were able to feel around and found the children in a bedroom next to the room where the fire was burning. The apartment interior had a wall of smoke and the temperature was several hundred degrees.

The two boys were unconscious and not breathing, and firefighters rushed them outside to emergency medical technicians, who were able to revive the children.

The boys were taken to the hospital in critical condition.

By Saturday evening, the boys were in a hyperbaric chamber at the NewYork-Presbyterian/Weill Cornell Medical Center and were expected to survive.

Members of the fire engine company said they were grateful they were able to help.

"When you find somebody, especially a kid, it gets you going," said Croak. "It gets the blood flowing and it's pretty exciting. Especially when you get them outside and you are able to bring them back to life."

"It's definitely a good feeling. Being a father of two young children, you would do anything for your children. To help a family in their worst moment is a good feeling," said firefighter Paul Peterson, who helped keep the flames at bay.

Milagros Perez and her eight-year-old daughter were also hospitalized with minor injuries Friday.

Authorities say the father of Perez's children was not charged, as he did not live in the apartment.

Investigators were still trying to figure out Saturday how the fire started.