The incident took place at house number 786 - a number considered lucky, which proved otherwise here - in Zakir Nagar area under the jurisdiction of Jamia Nagar police station of south-east Delhi.
According to the fire department, following a call of fire at around 1.30 AM today, two fire tenders were sent to the spot which took almost 30 minutes to douse the fire completely.
Amid the flames, the trapped family members were taken out of the house and rushed to the Safdarjung hospital where Yasmin and Afreed, the mother-daughter duo, were declared brought dead while Firoz, Afroz and Aasif succumbed during treatment.
"The condition of Aamir, the lone survivor of the blaze, is said to be critical and the next 24 hours would be very crucial for him," said a hospital source.