An Olympic gold medallist was among those injured after a double-decker bus crashed into a railway bridge.
Kevin Young, a 400m hurdler whose world record at the 1992 games in Barcelona has still not been beaten, tweeted he suffered “broken ribs and head trauma”.
A woman is in critical condition after the bus, bound for Swansea University, crashed into the bridge on Neath Road, Swansea at 09:40 GMT on Thursday.
A 63-year-old man arrested on suspicion of dangerous driving has been released.
Two other people were seriously hurt, while others are in a stable condition.
American Mr Young said it was a “tough day trying to get to class”.
He is among a group of seven former Olympians to be the last students to take on a degree at Swansea University before the course moves to Belgium.
The course – a master’s in sports ethics and integrity – aims to teach future sports administrators about anti-doping, illegal betting and child protection.
The bus was travelling from Swansea University’s Singleton campus to its Swansea Bay campus.
A First Cymru spokesman said the bus was off its normal route due to a temporary road closure.
Network Rail said the height restriction on the bridge is 3.3m (11ft) but the sign was dislodged in the crash.
In a statement, South Wales Police thanked the public “for their patience while the road was closed” and asked any witnesses with dash cam footage to contact them.