Fourteen people were injured at a bonfire event when fireworks malfunctioned and shot into the crowd.
The display at the Antrobus Hotel in Amesbury, Wiltshire, on Saturday night was cancelled soon afterwards.
A number of young children were among the 14 people injured, who were all treated at the scene.
Wiltshire Council said the authority was investigating what happened at the display and would be liaising with the hotel.
The Health and Safety Executive said it would only investigate if the council decided it was appropriate.
The hotel said "a single display box, containing multiple fireworks, malfunctioned" and said it called an end to the display as soon as it happened.
In a statement, it added: "Regrettably, despite the safety cordon exceeding the manufacturer's guidelines, some projectiles ejected towards the crowd line.
"We are mortified about what has occurred today and would like to apologise to all those affected, please rest assured that a full investigation will take place."
Lewis Foote, who was at the event with his wife and sons, aged one and three, said: "I saw on the right hand side there was a picnic bench and people were sitting there having a drink and a firework went off on the bench right in front of them.
"I thought that ain't right and then another one flew straight into the crowd."
Mr Foote said it had felt overcrowded and nobody was counting numbers on the door.
"There was a lot of panic and kids crying, it was quite scary," he added.
"We were crammed in and all we could do was turn our backs and shield our faces."
Rachael Tomlinson, who was at the front with her daughter, said she was hit in the face by a firework.
She said: "I was a bit shaken as it was really close to my eye. The ambulance crews put ice on it.
"I saw a lady in the toilet whose hat was black where it had been burnt and another lady had to put her hat out because it caught fire.
"I saw a little boy with five burns on his face and he was really shaken up."
'Scarred for life'
Many of those who attended have taken to Facebook to voice concerns over how the display was handled and to complain that videos they had posted on the event's page had been deleted by organisers.
Natalie Morris said: "After things went bad there was no shelter and no safety exits so we were sitting ducks, fireworks coming over the top of us and exploding at our feet, sheltering kids with ourselves.
"We are all traumatised but safe, my daughter plucked up courage to try and enjoy fireworks and has now been scarred for life."
The hotel has been asked to comment further.
A spokesman for Wiltshire Police said they were called to the scene at about 20:10 GMT, to reports of fireworks in the crowd.
The force said no arrests have been made.
Fire crews and ambulances were also in attendance, and South Western Ambulance Service said it treated 14 people at the scene.