Unnao (UP), Sep 20 (PTI) Three workers were killed after awall of a factory here fell on them following explosion of twocylinders kept in the premises, police said today. Sanju, Vinod and Sunil were killed last night after thewall, of the dog food manufacturing factory at Dahi ChowkiIndustrial area, collapsed on them due to the explosion, theysaid. A case of negligence has been registered against thefactory management, police said. PTI COR SAB ANB SMJGVS