Relatives of 27 of the 33 men trapped in a Chilean gold and copper mine are suing their bosses for £6.3 million.
The families of the miners, trapped since August 5, will demand a similar amount from Chile's government in the next few days, their lawyer Edgardo Reinoso said.
Relatives accuse Alejandro Bohn and Marcel Kemeny, owners of the San Esteban mining company, of negligence and breaches of several workplace and mine safety regulations. The second suit will claim the government failed to enforce the regulations.
"We families want them to pay all the damages, and we want justice," said Elvira Valdivia, noting that her husband, heavy equipment operator Mario Sepulveda, will have to spend his 40th birthday half a mile underground on Monday.
Most of the miners' families agreed to sue last month during a meeting at Camp Hope, where they have been maintaining a vigil.
Relatives of the remaining six miners will have to decide whether to pursue their own lawsuit, join this one or leave it alone, Mr Reinoso said.