Eighteen school children were killed in China when an overloaded school bus collided with a truck in Gansu province.

Sadness has lead to outrage as Chinese officials blamed overcrowding for the tragedy. The minibus had only nine seats, but was reportedly carrying 64 people, most of them 5 and 6-year-olds on the way to a local kindergarten.

Four of the children died at the scene, while 14 died at a nearby hospital. The bus driver and a teacher were also killed, and 45 other children were injured.

The crash was the fifth school bus accident in China this year.

As is becoming increasingly common in China, angry citizens took to social media networks and microblogs to express their opinions of the event.

The nursery school can't shirk responsibility for such serious overcrowding, commenter Sina said on Weibo, a Twitter-like Web site.

Why don't we protect children in the same way we protect our leaders? another said, according to Reuters.

The rapid growth of China's economy over recent years has resulted in a dramatic increase in car ownership. In 2010, 18 million new passenger cars appeared on Chinese roads, the majority of them domestically made. But, with cars being a relatively new social phenomenon, safety and driving standards have been slow to catch-up, often making streets dangerous and anarchic places.

More than 100,000 people die in car accidents in China annually, according to the Los Angeles Times, making China's roads the deadliest in the world. Last year, there were more than 600,000 car accidents, about a tenth of them resulting in death.

This accident says a lot about the problems with the government's role of monitoring school safety, Liu Shanying, an expert in public administration at the state-run Chinese Academy of Social Sciences, told The Associated Press. It involves the education, traffic safety and work safety authorities. They should all be blamed for this. They should all be held responsible.

The kindergarten van was carrying seven times as many passengers as it should have been, which meant the kindergarten should have bought seven times as many vans, Liu said.