NASHVILLE (AP) - Officials at a Gallatin iron dust factory where five people died in accidents last year were aware that the dust could explode but did little to mitigate the dangers, a federal investigative agency has concluded.

The U.S. Chemical Safety Board on Thursday released its final report on three accidents over the first five months of 2011 at a Hoeganaes Corp. plant.

It found that the company made plans to improve safety after an insurance review but did not follow through.

CSB Chairman Rafael Moure-Eraso said at a news conference on the report that the company knew the dangers and "decided to take the risk."

In a news release, Hoeganaes said it has taken action to prevent future accidents and ensure the plant operates at "world class standards."