Firefighters were called to the blaze at Busy Bees nursery in School Lane at around 1.30pm on Tuesday, which has badly damaged the roof space.
>>>Click here to see pictures of from the scene.
All of the children and staff were safely evacuated from the building, with youngsters temporarily accommodated in local houses, an Italian restaurant and at another nearby nursery school before parents could collect them.
>>>Click here to read about the community efforts to help the nursery.
Now a fact-finding mission is underway to establish the cause of the fire and to decide what repair work is required.
A spokesman for Busy Bees said: “Our Bamber Bridge nursery is temporarily closed while structural engineers assess the damage and we’re working with the authorities and regulators to establish the facts.
"We remain committed to communicating with families and will keep them informed of the ongoing situation. In the interim, children are being cared for at two of our nearby nurseries Busy Bees Chorley Brooke Street and Busy Bees Ashton House where we have a team of friendly faces ready to greet them to help maintain consistency during this time.
“We would like to thank the efforts of the Lancashire Fire and Rescue Service for their assistance and prompt attendance, and praise our team for their professionalism during the emergency situation. We also extend our gratitude to parents for their patience and understanding as we appreciate the impact it may have on their family.
“We continue to ensure our centres are a safe haven for children to thrive, learn and develop and we hope it won’t be long until we can reopen our doors once again.”