Latvia's PM Valdis Dombrovskis has announced his resignation, and thereby the fall of his government, over the deadly collapse of a Riga supermarket.
He made the announcement at a meeting with President Andris Berzins, Latvian and other media reported.
"The country needs a government which is capable of resolving the situation which has emerged," he was quoted as saying by the Baltic news agency Delfi.
At least 54 people died when the supermarket collapsed last Thursday.
President Berzins earlier described the disaster at the Maxima store as "murder" and called for foreign experts to investigate what had happened.
The prime minister's spokesman told the AFP news agency on Wednesday that "the government takes political responsibility for the tragedy".
According to Delfi, Mr Dombrovskis met the president for an hour and a half, during which Mr Berzins appears to have called on him to take responsibility for what happened.
"I call on all who look to the future to assess their responsibility and act accordingly," the president was quoted by the agency as saying.
The collapse was the biggest loss of life since Latvia became independent from the USSR in 1991.
Police have opened a criminal investigation into the cause of the disaster.
Structural experts have suggested that the supermarket building itself may have been badly designed and so not able to support a garden which was being built on the roof.
After analysing photos, videos and eyewitness reports, one structural engineer suggested there had been numerous design flaws in the roof's supporting beams - including not enough bolts.
Substandard construction materials and corruption are other possible lines of inquiry.
Mr Berzins can either reject his prime minister's resignation or accept it and nominate an acting prime minister whose job it will be to form a new cabinet.
Taking office in 2009, Mr Dombrovskis was charged with making harsh budget cuts and tax increases as well as tough structural reforms to tackle the country's economic crisis.
He was twice re-appointed, and is widely credited with preventing the small Baltic country from going bankrupt.
Latvia is due to join the eurozone on 1 January, becoming the 18th EU state to adopt the single currency. (BBC)