Hewitt says the shooting in the break room of the plant on the city's northwest side was reported about 6:30 p.m. Friday. He says another person was in the break room and saw the shooting.
The man who shot himself died at the scene. The other man was taken to a hospital and died there.
Hewitt says investigators don't know the motive for the shooting. He didn't know what type of firearm was used.
Con-Agra manufactures brands including Banquet, Hunts and Chef Boyardee.
A spokeswoman didn't respond to a call seeking comment.