A fire which severely damaged a Premier convenience store was "deliberate", investigators said.
Essex Fire Service were called to the shop on London Road in Westcliff-on-Sea at 01:16 BST.
When crews arrived 50% of the shop was on fire and flats above the store had to be evacuated.
Essex Police said it was treating it as arson and officers were seeking a man on a mobility scooter who was seen outside the property.
Eyewitness Selina-Louise Allen said firefighters had to "rip the shutters off" the front of the shop to tackle the blaze.
"At around 01:00 I heard the alarm going across the road, so I went to the window and the firefighters were there, three trucks in total," Ms Allen said.
"They were fighting the blaze and trying to get into the shop, trying to rip the shutters off.
"They were battling for about an hour and it was out by 02:00."
A fire service spokesman said: "The cause has been recorded as deliberate."
Essex Police made a request for witnesses, CCTV or dashcam footage.
Officers said a man was seen on a mobility scooter outside the store just before 01:10 and they would like to speak to him in connection with the investigation.