The incident occurred at around 0315 hrs, as the blaze started due to a short-circuit in the air conditioner in the intensive care unit (ICU), hospital sources said.
Fire fighters rushed in and extinguished the fire by 0530 hrs.
The Chief of the RDMC of the TMC Santosh Kadam said a total 17 patients were in ICU, of them 13 were killed and four others were rescued as they have been shifted to nearby hospital.
The deceased were identified as Uma Suresh Kangutkar (63), Nilesh Bhoir (35), Pritviraj Vallabhdas Vaishnav (68),Rajni Kadu (60), Narendra Shankar Shinde (58), Janardhan Moreshwar Mhatre (63), Kumar Kishore Doshi (45), Ramesh Upayan (55), Pravin Shivlal Gauda, (65), Amey Rajesh Rahut (23), Shyama Arun Mhatre (48), Suvarna Pitale ( 64) and Supriya Deshmukh (43). UNI