The toll in the Visakhapatnam Steel Plant accident rose to 12 on Friday, with one more employee succumbing to burns in a private hospital here. An explosion occurred on Wednesday night in the oxygen plant of the steel melt shop of the Rashtriya Ispat Nigam Ltd. Mr K. Srinivasa Rao, Senior Manager, died on Friday in the hospital. Two employees - Mr D.S. Kalsi (General Manager - Projects), and Mr L. Srinivasa Rao, Assistant General Manager, were flown to Mumbai on Thursday evening for treatment. Two more employees were flown to Mumbai on Friday - Mr P. Narayana Rao, Senior Chargeman, and Mr M.B. Muralidhar Raju, foreman. Mr R. Bhattacharya, an employee of M.N. Dastur and Co, who sustained serious burns in the accident, would also be flown to Mumbai later, it is learnt.