Five girls have died after their school bus crashed when taking them home in Ireland.
It's prompted a lot of debate among kids in Ireland and across the UK, especially as the girls' bus was not fitted with seat belts.
CBBC Newsround Online has investigated the rules for the UK and the issues surrounding them.
When must kids wear seat belts?
Seat belts must be fitted in coaches and minibuses on organised school trips.
Home-to-school buses are often buses which are used for regular services, which are not fitted with seatbelts. They are not required to be fitted with seatbelts for home-to-school trips.
Schools or education authorities can choose to hire buses that have seat belts, but it is not compulsory.
Is it true that kids under 14 can travel three-to-a-seat?
Three children are allowed to travel on a bench seat designed for two adults, but schools and education authorities can choose whether or not to do this.
The government said a recent survey showed that only a small number of schools were still choosing to allow this.
What is the problem with this?
The rule has been in place for a long time. Some groups say that it should be scrapped because kids are bigger than they used to be and they have to carry a lot more stuff to school, so there is not enough room for three kids on a seat.
How common are school bus crashes?
They are quite rare, but several children have been killed in these type of accidents in recent years.
What is being done about the problem?
Campaign groups - sometimes set up as a result of these accidents - have been formed to make kids' school journeys safer.
Some of the things the groups are campaigning for include making all kids wear seatbelts, scrapping the three-to-a-seat rule and putting adult supervisors on school buses.