A series of blasts ignited by methane gas ripped through the Pike River Mine on the west coast of the South Island in November 2010, trapping 31 men, though two managed to escape, Reuters reported.
Safety concerns prompted the previous government to rule out reentry, despite opposition from the families of miners.
“New Zealand is not a country where 29 people can die at work without real accountability,” Andrew Little, the minister responsible for the operation, said in an email.
“That is not who we are. And that is why today we have fulfilled our promise.”
Families of the men gathered near the mine entrance as the experts entered, the statement added, an event delayed beyond an initial date of May 3 because of concerns over oxygen levels.
“Watching those doors open and seeing the light enter that dark tunnel for the first time in years was incredibly emotional,” Anna Osbourne, whose husband died in the accident, said in an emailed statement.
“This is the start of a journey that will end with truth and justice.”