On Nov 11, 2016, an iron ball suddenly dropped from a building in Suining, Sichuan province, killing a girl who wasn't even a year old.

The police collected fingerprints and DNA information from the ball and matched it with every building resident but could not confirm who threw it. The girl's family then sued the entire building. On Aug 27, the court asked every family residing in the building, except those who can prove they were not there that day, to pay 3,000 yuan ($439.1) in compensation to the girl's family.

The law forbids high-rise residents from throwing things from their windows. Those doing so should bear responsibility for any consequences. In fact, even if there is no damage, they can be charged with threatening public safety and face criminal charges for accidentally or intentionally injuring/murdering someone. Anybody can guess the damage an iron ball dropping from a window can cause. Therefore, the action can only be treated as intentional. However, such accidents keep happening and it is not always possible to pinpoint the suspect, as there might be hundreds of residents in a high-rise building.

As in the Sichuan case, the responsibility will have to be shared by all residents. However, for justice to be done the real suspect should be found and tried.

Maybe technology can help. There were reports on Monday that a residential community in Chongqing has installed a smart system that can trace any falling object to its thrower. If this system works, it can be applied everywhere. And law-abiding residents will welcome it, as they will not want to be punished for someone else's actions.

And when residents know that a system is tracking them, they will be more careful. Here's hoping that the law and technology prevent such tragedies from taking place.