According to CCTV news, at about 15:10 on March 30, a suspected flammable gas explosion occurred in the left hole of the Tiefengshan Tunnel in the Wanzhou-Kaijiang section (A2 contract section) of the Enshi-Guangyuan National Expressway, invested by Chongqing Wankaida Expressway Co., Ltd. and constructed by China Railway 12th Bureau Group Co., Ltd., causing one person to lose contact and 12 others to be injured. As of 0:00 on the 31st, the missing persons had been found and confirmed to have no vital signs. Three people died after being sent to the hospital after rescue efforts failed. At present, the on-site search and rescue work has ended, the construction site involved has been closed, the aftermath is being carried out in an orderly manner, and the accident investigation has been launched.
The tunnel entrance where the incident occurred
The tunnel entrance where the incident occurred
The tunnel entrance where the incident occurred
On the 31st, a reporter from Jimu News came to the scene of the incident for an on-site visit. The entrance of the Wankaida A2 Tiefengshan Tunnel on the Enguang Expressway is in Xiangliang Village, Gaoliang Town, Wanzhou District. It is located in a valley and there are multiple tunnels under construction nearby.
The 80-year-old Granny Tan's house is located on a hillside more than 100 meters outside the tunnel entrance. The explosion caused the wall of her house to fall. According to Granny Tan's recollection, she was watching TV at home when she suddenly heard a loud noise like a cannon. She was startled. When she went out, she saw white smoke filling the valley, and she could not even see the wooden houses outside the tunnel entrance.
The glass door of a house 100 meters outside the tunnel entrance was damaged
Iron sheets and other debris splattered after the explosion
There was a house below the tunnel entrance where the explosion occurred. Steel plates, iron sheets and other objects were splashed into the dam of the house due to the explosion. The glass door of the house facing the tunnel entrance was also damaged. The homeowner said she was lucky not to be at home when the incident occurred. In response to the damage to the house, the village and town have come to inquire about the situation.
Villagers said that the impact of the explosion was so strong that some iron sheets and plastic pipes were rushed to the opposite mountain more than 100 meters away. Workers working at the foot of the mountain were also injured.
Outside the tunnel entrance where the incident occurred
The reporter saw at the scene that the colored steel shed house built outside the tunnel was damaged. There were many white building fragments on the mountain opposite the tunnel entrance. Steel frames and pipes were washed to piers dozens of meters away from the tunnel entrance. Environmental emergency monitoring personnel were on site to monitor the gas. Villagers said that the workers working here were all from outside the area and had been on vacation after the explosion.
There is another high-speed rail tunnel project on the mountain more than 100 meters above the tunnel where the incident occurred. A staff member of the project said that when he heard the sound, he thought it was the start of cannon fire, and soon after he saw white smoke rising from the bottom of the mountain. In December last year, the high-speed railway tunnel was stopped after coal seams were dug and gas was detected. It was originally expected to start in April this year, but due to the impact of the high-speed tunnel explosion on the 30th, the start of construction may be postponed.
In July 2025, the official WeChat public account of China Railway 12th Bureau Group Fourth Engineering Co., Ltd. stated that the Tiefengshan Tunnel has various adverse geological conditions such as karst, gas, and fault fracture zones, making construction extremely difficult.
According to local media reports in Chongqing, the Wanzhou-Kaijiang section of the Enshi-Guangyuan National Expressway project includes more than 20 extra large bridges and 7 tunnels, with a bridge-to-tunnel ratio of 65.9%. The project is designed according to the standard of a two-way four-lane expressway, with a design speed of 100 kilometers per hour. The total estimated investment is about 11.26 billion yuan, and the construction period is 5 years. The project focuses on two extra-long tunnels, including Tiefengshan Tunnel with 8,635 meters and Wufu Tunnel with 6,437 meters.
