England public-place injury: does an occupier owe visitors a duty of care?

Yes. Under the Occupiers’ Liability Act 1957, an occupier owes lawful visitors a common duty to take reasonable care in the circumstances to see that they are reasonably safe while using the premises for the permitted purpose. Whether that duty was breached depends on the facts. Official source: Occupiers’ Liability Act 1957. Guide: https://getinstantlaw.com/public-place-injuries