Passengers escaped serious injury by ducking as their bus smashed into a rail bridge in Melbourne, peeling the roof back like the lid of a tin can.
Eleven of the 15 people on the bus, including four who needed to be cut free by fire crews, were admitted to hospital after it crashed into a low clearance bridge in South Melbourne at on Monday morning.
Witnesses said the roof peeled back like the lid of a can of sardines.
The fact the three metre high bridge was just a little higher than the heads of the 14 passengers had "significantly contributed to a good outcome", fire brigade commander Andrew O'Connell said.
He said it would have been absolutely terrifying inside when the roof was being destroyed.
"Luckily, hopefully, they all ducked their heads and closed their eyes to keep themselves out of trouble," he said.
Nicholas Alexander was driving behind the bus and says he tried in vain to warn the driver of the imminent disaster.
"When I saw that he was not indicating and heading for the bridge I started blowing my horn," Mr Alexander told AAP.
After the impact, he and another witness used a ladder to climb through a broken window to check on passengers.
"There was a woman asking for help and bleeding from the head, but everyone was conscious and it could have been so much worse," Mr Alexander said.
Mr Alexander and other witnesses said collisions were so commonplace at the bridge, they were no longer surprising.
Silvio Parisi and Nalin Wijesundara pointed to footpaths near the bridge that are covered in debris left behind from previous collisions.
"I've been working here for 12 years and I've seen this happen at least once a week, sometimes two or three times a week," said Mr Parisi.
Police will try to uncover how the driver managed to ignore warning signs and lights.
VicRoads will review the warnings but say driver error was involved in the latest crash.
Gold Bus Ballarat said it is working closely with emergency services. The driver was one of the 11 who was injured in the crash.
