A man was sent to hospital after undergoing burn injuries in a suspected gas outbreak at a shop.
West Midlands Fire Service was called to the scene in Holyhead Road in the Handsworth area of Birmingham at 14:36 BST on Thursday.
The explosion blew out the front window of the building and caused a rear wall to collapse, the fire service added.
Three people were also "led to safety" by firefighters from a first-floor flat.
A structural engineer was called to assess the safety of the building, with utility companies deployed "to isolate power supplies".
The cause of the outbreak is not yet known. (BBC)