Monday, 23 miners, who were reported missing underground, were found and rescued by emergency teams, but another 13 workers were still trapped.

According to Reuters, the miners went missing underground after a gas explosion at a coal mine. They were brought to the surface through a ventilation shaft. The main shafts couldn’t be used because of the damage.

Maryna Nikitina, a spokeswoman for the regional mine safety inspectorate, said that the rescue teams went into the mine to save 21 workers. Two miners were rescued earlier. She also said the rescue crews found one dead man.

Apparently, at the time of the explosion, the miners were 1,000 meters ( 3,300) feet underground, trying to improve the Karl Marx mine so that it would be a safer place.

According to the International Herald Tribune, deputy Prime Minister Oleksandr Turchynov said that the ventilation system was still working and there was the possibility that more workers were alive. Five workers who were above ground have also been injured and they were transported to a hospital.

The Karl Marx mine was known for its unsafe conditions and its activity was suspended so that workers would improve its safety conditions. According to the International Herald Tribune, Ukraine has many dangerous mines. More than 4,800 miners have been killed since 1991.

The Karl Marx mine is situated in the eastern Donetsk region, about 640 kilometers ( 400 miles) southeast of Kiev, the capital of Ukraine.