The fire erupted in a rear storeroom
A firefighter remains critically ill with extensive burns after tackling a Halloween night blaze in County Londonderry.
Six others were less seriously injured trying to rescue him from the fire at the Gorteen House Hotel in Limavady at about 0200 GMT on Saturday.
It is thought the critically injured firefighter fell into the flames after the roof of an external storeroom at the back of the hotel collapsed.
The injured were taken to Altnagelvin Hospital in Londonderry but six of them were discharged after being treated for the effects of breathing in smoke.
Northern Ireland's Chief Fire Officer Colin Lammey spent the day with the injured man's family.
He said: "Any incident at which a firefighter is injured is serious and my thoughts at this time are with the injured firefighters and their families.
"The brigade has launched a full enquiry into the circumstances surrounding last night's incident and I await the outcome of these investigations."
The cause of the fire, which began in the storeroom, is currently being investigated.
Chief Fire Officer Colin Lammey: Brigade launched full inquiry
Meanwhile, the Fire Brigade has condemned attacks on firefighters during Halloween night.
Crews responded to more than 500 calls during the busiest night of the year.
But a number of crews were targeted while responding to calls relating to bonfires in County Armagh.
In Bessbrook, the windscreen of a fire engine was smashed by youths throwing stones.
Firefighters also had to turn back after facing hostile crowds in Newtownhamilton and Keady.
Assistant Chief Fire Officer Peter Craig said such attacks were appalling.
"It's been disappointing to have to report that once again, our firefighters who were out there trying to serve the community and protect the community have come under needless attack," he said.