Sixteen people were killed after a fire broke out at a shopping mall in southwest China on Wednesday, according to Chinese state media.

Dramatic images showed a huge column of black smoke billowing from the 14-story building in the city of Zigong, Sichuan province. Several people were also seen gathered on a balcony.

About 30 people were rescued from the blaze after nearly 300 emergency workers and dozens of vehicles were dispatched from the local fire department to the scene, state broadcaster CCTV reported.

Preliminary investigations suggest the fire was caused by construction work, CCTV said, citing local authorities.

In a statement Thursday, China’s Ministry of Emergency Management urged rescue workers and provincial officials to determine the cause of the fire as soon as possible, and to learn lessons to ensure greater security in the future.

Such incidents are not uncommon in China, where enforcement of safety standards is often lax.