MSHA started providing assistance to Pike River mine management on Sunday.
“A team of five top mine emergency experts from MSHA, along with one of the only robots in the world designed to travel in potentially explosive underground coal mine conditions, were en route to the minesite via Los Angeles when they learned of the second explosion,” the government safety authority said.
“We are gratified that we were able to offer assistance to New Zealand during this extremely difficult time.”
Two army landmine-disposal robots were deployed into the main access tunnel this week.
The robots were risk assessed but not rated as intrinsically safe, which can take many months.
A tunnel inspection vehicle from the Water Corporation in Western Australia was being prepared for deployment before the second explosion hit on Wednesday afternoon.
This explosion is thought to have been triggered by smouldering material in the mine left over from the first explosion last Friday.
"Our deepest and most heartfelt condolences go out to the families of the 29 miners who died at New Zealand's Pike River Mine,” MSHA said.
“While our nations may be separated by thousands of miles, we are united in grief, given that a similar disaster befell 29 US miners in April [at Upper Big Branch].”
The Pike River mine disaster is the biggest in the country since 43 men died from an underground gas explosion at Ralph’s mine in Huntly back in 1914 – another coal operation.
While the coal market is booming, 2010 has been marked by several major mining disasters.
The month after the UBB tragedy, two underground gas explosions rocked the large Raspadskaya mine in West Siberia.
Bodies are still being retrieved, with the death toll at 75 but likely to go to 91 when all the missing men are found.
China’s coal industry, with its deep gassy mines, is often plagued by disasters, but the government is making serious inroads into overhauling safety.
“While coal mining accidents seem to have dominated the headlines this year, we can be thankful that one recent event did not end in tragedy,” MSHA said.
“Earlier this week, 29 miners in China were successfully rescued just one day after their mine flooded."
A total of 41 workers were underground at the Batian coal mine in Sichuan province when it was flooded on Sunday, with almost one-third managing to evacuate right after the incident.