Incredible video and pictures have caught the moment a series of blasts ripped through a densely populated district in Taiwan's second-largest city.
The explosions killed 25 people and injured nearly 300 in what is believed be the country's deadliest ever gas explosion.
Streets were blown apart with bodies, vehicles and debris strewn across roads. The force of the explosions also hurled concrete through the air and blasted long trenches in the streets. The cause of the underground blasts in Kaohsiung are unknown.
The series of five explosions about midnight Thursday and early Friday struck a densely populated district where petrochemical companies operates pipelines alongside the sewer system in the southwestern port city of 2.8 million people.
Witness Chen Guan-yuan, who was at the scene shortly after the blast, told the BBC, "I saw lots of cars and motorcycles with engines all over on the road, and doctors checking if bodies were dead or alive."
Firefighters called to the neighborhood in the late evening to investigate a gas leak were among the victims when the blasts went off hours later, upending at least six fire trucks in the rubble of pavement and dirt.
Four firefighters were among the 25 dead as well as some of 267 people injured, the National Fire Agency said. The death toll could rise, because many of the seriously injured were still being treated, officials said.
Three people also were reported missing in the disaster, Taiwan's second in as many weeks following a plane crash that killed 48 people on July 23.
"Last night around midnight, the house started shaking and I thought it was a huge earthquake, but when I opened the door, I saw white smoke all over and smelled gas," said Chen Qing-tao, 38, who lives 10 buildings away from the main explosion site.
The fires were believed caused by a leak of propene, a petrochemical material not intended for public use, but the cause and source of the leak were not immediately clear, officials said.
The exploded gas line belongs to government-owned CPC Corp, which told The Associated Press it showed no signs of problems before the explosions. CPC officials at the scene Friday declined to offer information about reasons for the blasts.
Video from the TVBS broadcaster showed residents searching for victims in shattered storefronts and rescuers pulling injured people from the rubble of a road and placing them on stretchers while passersby helped other victims on a sidewalk. Broadcaster ETTV showed rows of large fires sending smoke into the night sky.
Chang Jia-juch, the director of the Central Disaster Emergency Operation Center, said the leaking gas was most likely to be propene. The source of the leak was unknown. Chang said, however, that propene was not for public use, and that it was a petrochemical material.
One of the fires, along a 33-foot stretch of gas line, was still burning into midday Friday, the National Fire Agency says on its website.
The government's disaster response center said it was trying to prevent any knock-on gas explosions in the same place or nearby.
"In terms of what we can prevent, we're afraid another explosion could happen, as there is that possibility," said Hsu Lee-hao, an economics affairs ministry section chief staffing the disaster response center. "We're afraid it could be in the same place or elsewhere."
Most of the injured were people outside on the street, often hit by rubble blown toward them or crushed by cars sent flying in the blasts, a police officer at the scene said. Police and firefighters were burned while trying to control blazes.
"I wanted to check on my friend working in the night market, but she was hit by rubble and is now still in the hospital," said Chang Bi-chu, 63, the door to whose house was warped by one of the blasts. "On the way I saw dead bodies. I felt really bad. After all there was just the air crash in Penghu last week."
A TransAsia Airways prop jet that took off from Kaohsiung crashed July 23 while trying to land in stormy weather in an archipelago in the Taiwan Strait. The crash killed 48 people and injured 10.
"The power is cut off in my house, there is no light and the fan doesn't work," Chang added. "We don't have money to stay in a hotel and they're all booked anyway."
Kaohsiung Mayor Chen Chu said several petrochemical companies have pipelines built along the sewage system in Chian-Chen district, which has both factories and residential buildings. She warned people Friday to stay away.
"We have an intersection . that's still burning," Chen said at an emergency government meeting broadcast on television. She called the explosions Kaohsiung's worst gas-related accident in 10 years. "The city of Kaohsiung has opened nine relief shelters. We hope people can first evacuate to a safe place."
More than 1,100 had evacuated overnight.
Rescue workers expected to find few, if any, people in the rubble because no buildings collapsed, Hsu in the disaster response center said.
When police officers and firefighters investigated the major leak on Kaixuan Road Thursday evening, they could not block it because they had not identified the source of gas. Those authorities were closest to the fire during the first explosion and therefore suffered burns.
People killed and injured elsewhere were standing, walking or driving in the streets, which are near a night market. On Friday afternoon, paramedics and a rescue dog combed the neighborhood for survivors.
Power supplies to 12,000 people in the area were severed, and 23,600 lost gas service.
The fire department received reports from residents of gas leakage at about 8:46 p.m., and the explosions started around midnight.
Closed-circuit television showed an explosion rippling through the floor of a motorcycle parking area, hurling concrete and other debris through the air. Mobile phone video captured the sound of an explosion as flames leapt at least 9 meters (30 feet) into the air.
One witness said he tried to help before paramedics arrived.
"I was on my scooter just across the street, suddenly there was the explosion, a white car was blown toward me, and I saw the driver trapped in the car," said Wong Zhen-yao, 49, owner of a car repair shop in the disaster area.
"There was still fire nearby. I tried to pull the guy out but couldn't," he said. "Only after the smoke was gone did I realize there was such a big hole in the middle of the road."
The explosions left large trenches of up to a meter deep running down the centers of four of the hardest-hit roads. The trenches were littered with soot-covered cars and pieces of pipe and edged with pavement slabs torn apart by the blasts. Burnt walls and toppled signs of shops lined Sanduo Road, near an elementary school.
The blasts affected an area of two to three square kilometers, much of it sealed off.