Several others were injured in the incident and were rushed to the King Edward Memorial (KEM) Hospital and the Sion Hospital.
The doctor who performed the postmortems said that all the 14 deaths were due to suffocation.
‘Postmortem reveals that all the 14 deaths were due to to suffocation,’ Dr Rajesh Dere said.
The fire broke out shortly after midnight on the third floor of the four-storeyed building on Senapati Bapat Marg, a commercial hub of the city, a civic official told PTI.
The building, in Central Mumbai, houses some commercial establishments including hotels.
According to the official, the cause of the fire is yet to be ascertained.
Several fire tenders, water tankers, emergency ambulances and police personnel rushed to the spot for the rescue operation.
An FIR has been registered against the restaurant ‘1 Above’ where the fire initiated in Mumbai’s Lower Parel locality.
The case has been filed under setion 304 (charges of culpable homicide) of the Indian Penal Code (IPC).
Transmission of the television channels ET Now, Mirror Now, Zoom and TV9 Marathi were affected due to the fire.