After a powerful storm left the Brandao family without power for a few days, they used a generator for short periods of time to keep their Brockton, Massachusetts home warm and their food unspoiled.

Unfortunately, the generator was emitting carbon monoxide and dangerous levels of the poisonous gas were expelled into their home. Marcelina Brandao said she had a headache for a few minutes, and then became unconscious from inhaling the carbon monoxide fumes.

“I thought it was just a headache, then 2-3 minutes I didn’t feel anything after that,” Marceline told WFXT Boston 25 News.

It was then that her 9-year-old daughter, Jayline, sprang into action.

"I heard my dad screaming and saw my mom passed out," Jayline said. Her dad was still conscious, but was completely overcome by the fumes.

Jayline reached for her dad's phone, which was locked. She then held the phone up to her dad's face to unlock it so she could place a call to 911.

"She was so smart," Marcelina Brandao said. "If it wasn't [for] her to call right away, I don't know what would have happened."

Jayline also made sure her 7-year-old sister and grandmother got out of the house safely—they were unharmed by the carbon monoxide, but her mother was hospitalized.

Mom Marcelina tells WFXT she believes Jayline saved her life.

“Oh yes she did I wouldn’t be here if she wasn’t in the house," she said.

After authorities arrived, the Brockton Fire Department Chief Brian Nardelli told CNN that they detected carbon monoxide levels at 1,000 parts per million inside, which can be fatal.

According to the Consumer Products Safety Commission, sustained carbon monoxide concentrations above 150 to 220 ppm can lead to "disorientation, unconsciousness, and death."

Fortunately, Jayline's mom and dad are feeling much better and the whole family is safe thanks to the quick thinking and heroic actions of one brave little girl.