A forensic examination will be carried out to establish the cause of a fire at the home of Aidan O'Brien.
The blaze broke out at the family home of the champion trainer at Ballydoyle in County Tipperary at about 10pm on Wednesday night.
A Garda spokesman said people were in the house at the time but escaped unharmed.
The roof was extensively damaged before several units of the fire service brought the blaze under control.
Investigations are continuing but the cause of the fire is not believed to be suspicious.
O'Brien's son, Joseph, praised the work done by the emergency services.
"Thank God everyone was OK. We were very lucky. At least any damage done is material and can be fixed," said the young jockey from Dundalk, where he was riding on Thursday afternoon.
"All the family were very appreciative of the work done by the Cashel and Cahir fire service and by the Gardai."