NEWPORT – An Eastern Washington aerospace company has been fined $500,000 by the state Department of Labor and Industries, one of the largest penalties ever assessed by the agency.

The agency announced the settlement Thursday in its case against Zodiac Cabin & Structures Support LLC of Newport.

Seventeen workers were injured in an explosion at Zodiac’s plant in mid-July 2015. An L&I investigation completed in January 2016 found 17 willful violations, one for each worker who was injured and hospitalized. The company was originally fined $1.3 million.

Zodiac appealed the citation and the two parties reached the settlement.

The explosion at Zodiac Aerospace on July 14 was due to defective equipment and the lack of proper safety procedures, L&I said upon completion of its investigation. Zodiac Cabin was required to fix problems and will be subject to follow-up inspections.

The Newport plant has reopened. It makes plastics and other composite materials used in the production of airplane cabin interiors.