In 2017, 15 workers died on the job, according to the US Mine Safety and Health Administration.
This is a big jump on 2016's eight fatalities and the highest since 2014, when 16 people were killed.
The agency reported metal and non-mental mines (which includes aggregates) had 13 deaths in 2017, down from 17 in 2016 and 2015, and a big drop from 2014's total of 30.
The majority of the deaths came from hauling machine or vehicle accidents, the Associated Press reported.
The new head of the MSHA, David Zatezalo, said in a statement the US government under Donald Trump was committed to mine safety.
