BEIJING, Dec. 21 -- Fourteen construction chiefs have been sentenced to prison terms ranging from three to six years for negligence leading to a deadly accident on a Beijing construction site a year ago.

Ten workers were killed and another four injured on Dec. 29, 2014 in the collapse of a gymnasium they were building at Tsinghua University High School, the affiliated middle school of China's prestigious Tsinghua University.

Announcing its verdict on Monday, the court in Beijing's Haidian District said the construction chiefs instructed workers not to lay steel bars needed to reinforce the concrete structure. The bars' omission led to the building's collapse.

The fourteen, including officials from the construction firm and the company in charge of supervising the project, also failed to ensure safety protocols were being followed on site, the court said.

It gave another construction manager a suspended three-year prison sentence.