At least five minutes were wasted due to miscommunication that the blaze, which claimed nine lives in Delhi's north west district Kirari, was in a house and not in a cloth godown, Director of Delhi Fire Service Atul Garg said.
He also said the caller who reported the fire incident did not inform that there were people inside the building.
"If there is a fire in a godown, we send extra fire tenders. As we were informed about the fire in a house, we sent men and machinery as per that. But when a fireman went inside, he saw it was a cloth material godown and he called for extra fire tenders, which led to at least five minutes being wasted," Garg rued.
A massive fire ripped through a three-storey residential-cum-commercial building in outer Delhi's Kirari area early Monday, killing at least nine people, including three children, the second such incident in the national capital this month.
Garg said the firemen had to rescue the people using the adjacent house as the cylinder blast in the building had caused damage to the staircase.
"There was a single staircase in the house which was broken due to the cylinder blast and wall collapse," he added.
Locals and firefighters rescued three people -- Pooja, 24, her three-year-old daughter Aaradhya and niece Saumya, 10, -- after they jumped to an adjacent building to escape.
Those killed in the blaze were identified as building owner Ram Chandra Jha (65), residents Sudariya Devi (58), Sanju Jha (36), Guddan, Udaykant Chaudhary (33) and his wife Muskan (26), their children Anjali (10), Adarsh (7) and three-month-old Tulsi.