Yul Kwon:
Now up in South Korea, the executives of a chemical company are under investigation following a toxic leak late last month. The accident killed five workers and injured 18 others. Worse, a cloud of hydrofluoric acid covered nearby towns and farms. More than 3 thousand people needed medical treatment for eye and lung complaints. Several hundred are in temporary shelters. And the government has declared the whole region a special disaster area. We have two reports from our broadcast partner MBC. The first is on how the accident likely happened.

Reporter:
This footage was recorded by a security camera right before the accident. Two workers on a tanker truck are connecting a hose, which uses air pressure to force hydrofluoric acid to the storage tank.

A foreman and a pump repairman are under the tanker. Suddenly a huge cloud of hydrofluoric acid pours out. The workers collapse. Five people, including the four workers on the spot, and one inside the factory, died in the accident.

Police believe that the worker on the left mistakenly knocked the gas hose out of its connection.

Since the flange which connects two valves linking the hose to the tank was loose, the gas rushed out as soon as workers started to send air into the tanker.

Police say that the workers had violated safety rules. They should have connected the air hose first, then connected the gas hose. But they tried to do both at the same time to get the job done quickly.

Seo Woon-sik:
They didn't have any safety equipment and the work order didn't follow the proper process. Therefore, they are responsible on these two points.

Reporter:
Police will take action against the company's officials, including the CEO of the company and the plant manager. Police also will investigate whether regulators were properly supervising the plant.

Reporter:
This is the town of Bongsan-ri which was struck by hydrofluoric acid from the Gumi factory. Though the field is full of rice, the grains drop from the stalks. At this fruit farm, more than six tenths of a mile away from the factory, apples drop from the branches, and the tree leaves are burned.

Ripe grapes are ready for harvest, but no one will pick them..

Park So-deuk:
The leaves are all withered away. The vines are terribly damaged.

Reporter:
The town closest to the factory was directly struck by hydrofluoric acid gas. This is where the impact of the hydrofluoric acid gas was direct. In the 30 minutes I've been in this town, I haven't seen any inhabitants at all. It seems like a ghost town. Let me go inside this house.

The door is open like this, and the pile of laundry shows how sudden the evacuation was. Frightened people left the town after the emergency evacuation order.

Hong Kyung-hwa:
The town was a mess. Babies were crying, and people were shouting. It was like a battleground.

Reporter:
However, farmers are coming back to take care of the fully-grown rice and their penned up cows.

Park Myung-seok:
The cows were in severe pain. Since people are sick, the cows are sick too. People fled for their lives, but I can't tell how painful I felt when I left the cows here.

Reporter:
Two hundred and fifty residents left Bongsan-ri and were evacuated to a temporary shelter.

Lee So-boon:
What a mess! Yeah, though this shelter treats us well enough, but there's no place like my home. But I have no choice but to stay here.

Reporter:
This is Kim Joo-man for MBC News.