The incident took place in Dallupura village near Mayur Vihar Phase-III at around 10 AM.
Six children, aged below ten years, were playing in the vacant plot owned by one Vijender when the incident took place.
All of them were trapped under the debris. Rescue workers took them to hospital where five were declared brought dead.
"Five persons were killed in the incident. One person is critically injured," the officials said.
Officials said construction of a boundary wall of around ten feet height was being carried out in the plot. "The wall collapsed adjacent to Hindon drainage," they said.
