Joseph Ray Castillo, a resident of Mayflower street in Barangay Pembo, suffered fatal head and body injuries.
His uncle, Richard Castillo, whom he was with at the time the wall collapsed, was hurt.
Makati police department homicide division chief Senior Inspector Gary Reyes said the incident happened at around 5:20 p.m.
The victims were standing beside a 10-foot high concrete wall along Shamrock street when the structure suddenly collapsed.
Reyes said the soil behind the wall may have softened because of the rains, causing the structure to give way.
"It was an accident waiting to happen," police told The STAR. – Michael Punongbayan