A garden centre in the St Mellon's, which employs around 60 full time and part-time staff, will be closed for 'the foreseeable future' after it was destroyed by a blaze last night.
Nearby homes were evacuated at the height of the blaze though nobody was hurt.
It took firefighters around five hours to put out.
An investigation, which has been taking place all day, has now been determined accidental by South Wales Fire and rescue service.
Families who live near the garden centre were allowed back in to their homes in the early hours of Thursday morning.