Massiah Browne, a 7-year-old boy from Sacramento, California:

"I was just playing in the pool and then I saw a boy at the bottom of the pool," Massiah, a second-grade student, told "Good Morning America." "And I went to go get him."

Massiah was swimming with relatives at the apartment complex where he lives with his mom and brother. He was in the pool with a 9-year-old relative, Savannah. He noticed the 3-year-old boy, a stranger, with ihs mouth open and eyes open and dove down 6-feet deep water to get him, grabbing his arm and pulling him to the pool's surface. Then Savannah pulled the boy to the pool deck, where adults came to help and then called 911.

"Savannah brought him to his mom and then they did CPR on the boy and then they called the doctor," Massiah said.

Bystanders performed CPR on the boy and he was breathing by the time first responders arrived.

"The child was transported in critical condition with advanced life support efforts provided by Sacramento firefighters," the spokesperson said.

Massiah's mom, Tiara Delvalle, rushed to the scene from her apartment after being alerted by relatives who were with her son at the pool. She said she is in touch with the boy's mother and she reports he is doing well.

"It's a miracle," Delvalle said of the boy's survival.

Massiah's father, Marcus Browne, a boxer who competed for the United States at the 2012 London Olympics, said that although his son swims like "a fish", he was in shock when he learned of his heroic act:

"I just couldn't believe it," Browne said of his son, who also goes by his superhero nickname, "Siah Fire." "He's a good kid."

Awesome Massiah and Savannah!