A boy of nearly 2 years old and 80 centimeters tall was found drowned in a pool with water only 40 cm deep in Xi'an, the capital of Shaanxi province, and the parents are questioning the cause, Huashang Daily reported on Monday.

The drowning occurred at noon on Saturday when the toddler was playing with his 4-year-old sister and a 6-year-old neighboring boy. According to the father surnamed Liang, who is from Luoyang, Henan province and has a store in Xi'an, he learned of the accident from the 6-year-old and went to the pool some 100 meters from his store.

"I found my son in the water and immediately rescued and then took him to a hospital. However, he died after emergency treatment," Liang said.

The pool where Liang's son drowned was part of an abandoned cement mixing plant. Liang said he was confused about how his son drowned in water that was less than half his height.

A police investigation is underway.