There's a lot going on in the dramatic photo above, a screenshot from a cellphone video shot by a bystander Saturday on the Paris street below. We'll try to break it down.
The 4-year-old was being looked after by his father in Paris while his mother was elsewhere. The dad had left the boy alone and the youngster had wandered out on the balcony.
Neighbors told CNN the boy had actually fallen from the balcony above -- on the sixth floor -- but somehow caught himself on the railing below.
2. Why isn't the man above the boy pulling him to safety?
The man in the adjoining apartment, who gave his name as Florian, reached over a dividing wall and grabbed the boy. But he told CNN affiliate BFM TV that he feared the child might fall if he tried to pull him over to his balcony.
"I wanted to act carefully above all and I certainly did not want to risk the child's life," he said. Florian said he was encouraging the child to edge closer to him. "He had extraordinary courage."
3. Who is the hero climbing the building?
Mamoudou Gassama, a 22-year-old immigrant from Mali, was in the neighborhood to watch a football match when he saw a crowd gathering around the apartment building.
While others watched, he sprang into action, scaling the outside of the building before grabbing the child's arm and pulling him to safety. It took less than 30 seconds for Gassama to scale the building, earning him a "Spider-Man" nickname in some headlines.
"I didn't think about it, I climbed up and God helped me," he told French President Emmanuel Macron, who invited Gassama to the Elysee Palace and offered him French citizenship. Gassama also has been offered a job with the Paris fire brigade.
4. Where was the boy's father?
He had gone out shopping, French prosecutor Francoi