People inside escaped before fire crews arrived and no one else is thought to be involved in the fire at this stage.
Enfield's High Street is closed to traffic and people living in the area are being warned to keep doors and windows closed as a precaution against the heavy smoke. Firefighters are expected to be at the scene for some time this morning.
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"All it takes is for somebody to see me - and I could just die, just like that. I could want to go to the shop and not come home."
Before the killing, Peters searched the internet for "serial killers", "treatment of child killers in prison" and "premeditated murder".
Arriva Rail North, Greater Anglia and South Western Railway are all affected.