No fire alarm was heard when a block of flats was engulfed in flames in Barking, a London Assembly member has said.
Twenty flats with wooden balconies were destroyed and another 10 damaged in the fire in De Pass Gardens on Sunday.
Assembly member Andrew Boff said no fire alarm sounded during the blaze, which he said was “crazy”.
London Mayor Sadiq Khan said the “shocking” fire could have “easily resulted in fatalities”.
“I live nearby so I went to the building to help get people out”, Mr Boff said.
“At that time, only two floors were alight but when I came out, the entire building was in flames – perhaps something to do with these wooden balconies on the outside.
“I was also struck that there was no fire alarm. The fire alarms do not work – which to me, seems crazy.”
More than 100 firefighters tackled the blaze, which spread over six floors, for more than two hours.
The fire was put out by 18:00 BST and its cause is being investigated.
A man and a woman were treated for the effects of inhaling smoke. No other injuries were reported.
Resident Mihaela Gheorghe said she had concerns about the safety of wooden balconies on the flats.
“We raised several issues to the builder, the maintenance companies and the council about the safety of having all these wooden balconies,” she said, adding: “I was in my fourth-floor flat when the fire started.
“We ran out. The fire brigade came but they found it hard to find a water supply at first.”
Mukhtar Raja, who also lives nearby, said he saw flames when he looked out of his window.
“The heat was unbearable and it was spreading so fast. I went outside and filmed the footage with my phone.
“The fact it was a tall building and the speed at which the fire was spreading was scary.”
People affected by the fire were told to “take rest” at the Thames View Community Centre – about a mile away from the scene.