Six fire engines from Blackpool, Bispham, St Annes, Fulwood and South Shore attended to extinguish the blaze.
These were the scenes on Wednesday morning as the road remained cordoned off to the public as an investigation was launched:
1. Hill Street fire
Firefighters wore breathing apparatus and used two hose reels to bring the blaze under control. Photo: National World
2. Hill Street fire
Five casualties were treated by ambulance crews, with several neighbouring properties evacuated as firefighters battled the flames. Photo: National World
3. Hill Street fire
Fire crews remained at the scene at around 10am to dampen down any hotspots. Photo: National World
4. Hill Street fire
A joint investigation into the cause of the fire was launched alongside Lancashire Police. Photo: National World
5. Hill Street fire
Neighbours said they were woken by "screams and loud banging" before they were evacuated from their homes. Photo: National World
6. Hill Street fire
Next door neighbour, Kim, told the Gazette: “We got woken up by screaming and loud banging. We opened the window and there was loads of smoke coming in, it was everywhere." Photo: National World