UPDATE 1-Three dead in North Carolina ConAgra plant blast

(Updates death toll)

WILMINGTON, N.C., June 10 (Reuters) - Three workers died when an explosion caused a roof collapse at a ConAgra Foods Inc CAG.N processing plant in North Carolina, and more than 40 people were injured, the company and police said on Wednesday.

The 500,000-square-foot (46,000-sq-meter) plant in Garner, south of the state capital of Raleigh, employed 900 people in three shifts and made Slim Jim meat sticks, ConAgra said.

Tuesday’s explosion started a fire and blew out a wall that fell onto a row of parked cars, crushing them. People at the scene reported a strong smell of ammonia fumes.

The cause of the blast was unknown.

Omaha, Nebraska-based ConAgra said in a statement on Wednesday that three employees were found dead inside the plant. Police said a 43-year-old woman was among the dead.

Work crews brought in cranes and other heavy equipment to move pieces of debris to aid in the search, Garner Police Sergeant Chris Clayton said.

State workplace safety officials inspected the plant last July, but found no violations, the state labor department said. (Reporting by Jim Loney; Editing by Jane Sutton)