At the scene – Harry Low, BBC News reporterLocals have been hugging and laying flowers close to this small block flats all day. Passers-by stop to a look at the largely windowless second floor.Police forensics teams have been assessing the scene for clues as to what might have caused the fire they are now treating as arson. The police cordon has expanded, along with the number of emergency service personnel, as the seriousness with which this is being taken becomes apparent.