A spokesperson for West Sussex Fire and Rescue said: "Shortly after 6pm yesterday (16 August) we responded to a fire at Hawthorn Road, Littlehampton.
"Joint Fire Control mobilised two fire engines from East Preston and Littlehampton to the scene.
"Upon arrival fire found a small fire in an outbuilding.
"Firefighters extinguished the fire using one hose reel and a thermal imaging camera. Fortunately there were no casualties.
"The fire is believed to be of deliberate ignition."
1. Morrisons fire 2.jpg
Fire and Rescue crews at the scene. Photo: Derrick Chester
2. Morrisons fire 4.jpg
Fire and Rescue crews at the scene. Photo: Derrick Chester
3. Morrisons fire.jpg
Fire and Rescue crews at the scene. Photo: Derrick Chester