The owners of a banqueting suite have been fined £12,000 after a ceiling collapsed on hundreds of people during a school prom.
It came down at the Al-Miraj Banqueting Suite in Small Heath, Birmingham, in July 2017.
Six people, including two girls and a young boy, had to be treated by paramedics.
The owners of the suite and a builder pleaded guilty to health and safety offences.
The event was arranged by the Al Ameen School in Birmingham and was to have featured live performances from musicians and an awards ceremony for pupils.
Birmingham City Council said its investigation found a new suspended ceiling had been installed about 17 months before the prom.
However, detailed structural drawings were not submitted to the local authority for approval, as required under building regulations, and builder Peter Lakin instead used an unsuitable lighting layout plan, it said.
The ceiling collapsed when fixings to the original suspended ceiling failed due to being overloaded by the new ceiling, the council added.
The banqueting suite's owner, Jami Mosque and Islamic Centre (Birmingham) Trustees Limited, based on Coventry Road, Small Heath, had previously pleaded guilty to one count under the 1974 Health and Safety at Work Act.
It was fined £12,000 and ordered to pay court costs of £3,000 at a hearing a Birmingham Crown Court on 25 September.
Mr Lakin, 73, of Southfield Drive, Hall Green, had pleaded guilty to one offence under the same act at an earlier hearing.
He was given a four-month prison sentence, suspended for 12 months, and told to pay costs of £2,000.