The deceased has been identified as Muraslin while his friend Sohail (7) who was injured in the incident is battling for life at Guru Teg Bahadur (GTB) hospital.
The incident took place at around 1 PM near Seemapuri Bus depot when the duo were playing on a heap of garbage which was lying adjacent to the 8-feet concrete wall.
The wall suddenly collapsed and the kids were trapped under its debris following which locals rushed to the spot and started clearing the rubble to rescue the children.
"The two kids, who were unconscious by that time were pulled out from the debris with the assistance of fire officials and were rushed to the nearby Guru Teg Bahadur (GTB) hospital where Muraslin was declared brought dead while the condition of Suhail is stated to be critical," said a police official.
Both the child lived along with their families in the nearby slum area under the jurisdiction of Seemapuri police station.
A case has been registered under relevant provisions of the IPC and further investigations are underway.