WILMINGTON, North Carolina (Reuters) - A roof partially collapsed on Tuesday at a ConAgra Foods Inc processing plant in Garner, North Carolina, injuring some people and trapping others inside, the Garner Fire Department said.
"It is an active rescue scene," said Captain Bud Davenport of the local fire department. "There are reports of people still trapped."
The plant employed between 500 and 1,000 people and made potato chips and sausage, the Raleigh News and Observer said on its website.
A police officer told local television that three people were still unaccounted for and 20 people were sent to local hospitals, but was not aware of any deaths.
About a dozen people were exposed to toxic fumes and some suffered chemical burns in the collapse, which followed an explosion, according to local television that showed rescuers in hazardous-materials suits at the scene.
CNN said the roof fell in several places.
"There are collapses in the front, back and centre," local photojournalist Chad Flowers told CNN.
(Reporting by Bob Burgdorfer in Chicago, Pascal Fletcher and Jane Sutton in Miami; Editing by Pascal Fletcher and Will Dunham)