On the morning of the 5th, a reporter learned from the Publicity Department of the CPC Huzhu County Committee in Haidong City, Qinghai Province that as of 3:12 a.m. that day, with the all-out search and rescue efforts of relevant departments at the provincial, municipal and county levels, all three trapped persons in the collapse accident at the extra-long tunnel under construction on the Qinghai Jiaxi Highway had been found, and all were confirmed to have no vital signs. Follow-up arrangements are being carried out in an orderly manner.

At around 15:38 on the 4th, the JX-1 General Contracting Department of the Qinghai Jiaxi Highway project of Sinohydro Bureau 4 reported that a sudden collapse occurred in the right tube of the Huzhu Beishan Extra-long Tunnel (under construction) of the JX-1 section of the Qinghai Jiaxi Highway, and three people were out of contact.

At around 1 a.m. on the 5th, the reporter arrived at the scene of the collapse accident at the Huzhu Beishan Extra-long Tunnel (under construction) of the JX-1 section of the Jiaxi Highway in Huzhu County, Haidong City, Qinghai Province.

Photo shows an excavator clearing rock debris at a collapse site inside the tunnel. Photo by Hu Guilong

At the tunnel entrance, the reporter saw that the headlights of dozens of vehicles, including emergency communication vehicles and fire rescue vehicles, lit up the tunnel portal, and trucks carrying collapsed rock debris drove in from time to time. Dozens of rescue tents had been set up nearby, and public security, fire, emergency and communications rescue personnel were hurrying in and out.

The reporter entered the tunnel and found the road surface muddy and slippery, with various construction vehicles parked on both sides.

Photo shows the site of the extra-long tunnel under construction on the Qinghai Jiaxi Highway. Photo by Pan Yujie

About 3 kilometers from the tunnel entrance, the reporter saw the accident scene. The cross-section of the collapsed area was relatively narrow, some facilities erected at the top of the tunnel had been damaged, and rocks occasionally fell. Workers wearing reflective vests marked "Sinohydro Bureau 4" were directing an excavator to clear the piled stone material on both sides, and police lights flashed at the rescue scene not far away.

A worker at the scene said that there are still hidden risks of collapse inside the tunnel.

It is understood that at 20:00 on the 4th, the rescue department held the first meeting on the handling of the collapse accident at the Huzhu Beishan Extra-long Tunnel of the JX-1 section of the Jiaxi Highway. Based on the assessment by experts from the Qinghai Provincial Department of Natural Resources and the Provincial Department of Transport, additional rescue forces have been dispatched to carry out rescue work from No. 2 inclined shaft of the left tunnel. As of 22:00 on the 4th, 269 rescue personnel from emergency, fire, public security and other departments had been deployed, including 42 frontline rescue workers, and 14 pieces of rescue machinery and vehicles, including excavators, loaders, dump trucks and ambulances, had been put into use, with about 600 cubic meters of collapsed rock debris cleared.

Photo shows fire rescue tents set up at the scene. Photo by Qi Xiujuan

On the social platform account of "Sinohydro Bureau 4," the reporter saw that on May 13, Sinohydro Bureau 4 had conducted the 2024 "Comprehensive Emergency Drill for Underground Cavern Collapse" at the exit of the Huzhu Beishan Extra-long Tunnel of the JX-1 project of the Jiaxi Highway it was contracted to build.

The Qinghai Jiaxi Highway starts in Jiading Town, Huzhu Tu Autonomous County, Haidong City, Qinghai Province, and ends in Xihai Town, Haiyan County, Haibei Tibetan Autonomous Prefecture. It is the "second channel" from Xining to Lanzhou. With a total length of 215 kilometers, the Jiaxi Highway project is a key project in Qinghai Province's 13th Five-Year Plan for transport. The Huzhu Beishan Extra-long Tunnel on the Jiaxi Highway has a total length of 11,177 meters and is the longest highway tunnel currently under construction or already built in the province. The tunnel has a maximum buried depth of 769 meters at the bottom, with high ground stress and large deformation, and it also passes through seven fault fracture zones. The geological conditions are complex and changeable, and the construction risks are high and the difficulty is great.

The specific cause of the accident is still under further investigation.