A 61-year-old woman and her granddaughter were injured after jumping from a third-storey window to the floor below to escape a fire in their Lai Chi Kok flat yesterday. Two other children and a domestic helper from the flat in Mei Foo Sun Chuen were also hurt during the blaze and rescued by firemen. The three girls, aged between four and nine, were kept under observation at Princess Margaret Hospital while the two women were in stable condition. The exact family relationships were not known last night. The blaze broke out in the kitchen of a third-floor flat of the private estate in Nassau Street at 6am. It quickly spread and trapped the five people inside. They retreated to the balcony to escape the smoke. 'I heard people shouting for help for 10 minutes,' a witness said. 'The smoke was so thick, people had to come out and fight for breath.' The woman and her granddaughter leapt from a window and landed on a podium on the second floor. Hospital staff said their injuries were not serious. Firemen took 45 minutes to put out the fire. About 20 residents were evacuated. One resident claimed the rescue was delayed because construction work for the Kowloon-Canton Railway Corporation's West Rail made it difficult for fire engines to enter. But fire-squad commander Wong Siu-kwong said: 'There was no delay at all. Actually we arrived at the scene in four minutes but had to take a little time to deploy and get into position.'