Why did the house in Hengshui, Hebei collapse?

On the afternoon of May 29th 16: 07, the Public Security Bureau of Fucheng County, Hengshui City, Hebei Province received an alarm: a residential building in Xinji Village, Gucheng Town collapsed and some people were buried. Fucheng County Public Security Bureau immediately launched the emergency mechanism after receiving the police, and public security, fire fighting, hospitals and other units immediately rushed to the scene for rescue. Upon verification, there were 9 casualties, including 2 deaths at the scene, 3 deaths due to serious injuries and 3 deaths due to minor injuries. 1 person is being treated.

After preliminary investigation, the case was caused by the owner dismantling the load-bearing wall and changing the building structure without authorization. After the case happened, the local government immediately organized forces to rush to the scene to direct rescue and treatment. At present, the case has been put on file for investigation and compulsory measures have been taken against the suspect. Related work is progressing in an orderly manner.

Load-bearing wall refers to the wall that supports the weight of the upper floor. It is a black wall on the engineering drawing, and it will destroy the whole building structure if it is knocked out. Non-load-bearing wall refers to a wall that does not support the weight of the upper floor, but only separates one room from another. There is a hollow wall on the engineering drawing. Whether this wall has much influence on the building structure.