(edited version)Well, I don't know the specific case, but workers strikes in 1980-1981 were common accross the whole country, mainly coal mines, shipyard, steelworks as they were employing lots of people, so the strike was more visible (and dangerous - in Poland electricity is produced mainly from coal, so those strikes could literally paralyse the country), but also in academic centres, among actors and other people of culture/art etc.
Just read about
Solidarność (Solidarity) movement in 1980-81 and the
martial law introduced by the communist regime on
13th December 1981.
Reasons? Poverty, food shortages, oppressions (violations of citizen and human rights: censorship, no passports for most citizens, no freedom of speach, the leading role of PZPR - communist party - written down in the Constitution of Poland, very limited rights to public manifastations, in short - every aspect of social life ruled or at least controlled by the government. And did I mention no free election?)
Ziemowit coal mine strike was started shortly after the martial law was proclaimed, and it lasted till 22nd December 2009. It was a part of a big wave of strikes accross the country in response to the martial law.
You can read also some shorts articles on Wiki on similar subjects:
"Wujek coalmine - 9 people were killed"Martial law in Polandand maybe check the external links belows those short articles to find out more on the subject