A deadly blast at a chemical plant in the city of Yibin in southwest China's Sichuan Province has left 19 dead and dozens injured. Authorities are continuing to investigate the cause of Thursday's tragedy. Yang Jinghao reports from the site.

Huge explosions and violent flames. The deadly disaster claimed the lives of 19 workers at this chemical plant in Jiang'an County, sending another 12 to hospitals with multiple injuries.

TIAN HUAJIANG INJURED WORKER "I heard a loud bang just as I was walking up to the building to start my night shift, then I saw the flames. I was thrown to the ground instantly. I was trying to escape but I couldn't stand up."

Tian is the most seriously injured of the surviving workers, with a fracture to his right arm, slight lung damage and numerous burns. Most of his injured colleagues suffered different degrees of hearing loss due to the tremendous sound of the explosion.

DR. CHEN KANG SICHUAN PROVINCIAL PEOPLE'S HOSPITAL "From our evaluation of their injuries, all of the wounded are now in stable condition, and most are expected to recover within a week. We're also providing psychological assistance."

YANG JINGHAO YIBIN, SICHUAN PROVINCE "From here, we can see the blast and fire almost completely destroyed the plant. Broken glass can also be seen scattered everywhere after the windows of neighboring factories were shattered. It's still not known what caused this tragedy."

Experts from the Ministry of Emergency Management are working with local authorities for a complete investigation before a conclusion can be made. During a press conference on Friday, local fire department officials acknowledged the company that ran the plant had yet to pass required fire safety assessments, despite beginning trial operations months ago -- an oversight that reflects loopholes in supervision.

ZHU LI HEAD OF JIANG'AN COUNTY "We will actively cooperate with the investigation team to find the cause of the accident as soon as possible and hold those responsible to account."

What also concerns the public now is how the accident will impact the environment, especially as the Yangtze River, China's longest, flows through the county. Local environmental authorities say they are closely monitoring the air and water quality, which have not been affected so far as the results show.

WANG LIN, CHIEF JIANG'AN ENVIRONMENTAL PROTECTION BUREAU "We will continue to monitor the air quality. And during the cleanup of the accident site, we'll also take measures to ensure no pollutants are discharged into the Yangtze River."

Sichuan provincial government says a thorough inspection to eliminate potential hazards in plants producing dangerous materials will be carried out soon. YJH, CGTN, Sichuan Province.