The deaths of nine school children on Wednesday were due to a "reckless" driver who overtook several cars to get across a railway crossing, Western Cape Transport MEC Robin Carlisle said.
"I am devastated that young people lost their lives and others sustained injuries on their way to school because of the utter recklessness of the driver," he said in a statement.
"According to police and witnesses, a minibus taxi overtook several cars stopped at the crossing, and was struck by a train while attempting to navigate across the track between the lowered booms."
Four other children were in a critical condition in hospital while the driver remained in a stable condition at Kuils River hospital.
Carlisle visited the Buttskop level crossing in Blackheath, on Buttskop Road, outside Cape Town earlier on Wednesday and conveyed his condolences to the affected families and wished the injured a speedy recovery.
He vowed to work hard with the relevant authorities to ensure there was no repeat of such an incident.
"I will keep a close eye on the investigation to ensure that justice is served. I will also work together with Metrorail and law enforcement agencies to do everything humanly possible to ensure that a tragedy like this does not happen again."
Chris de Vos, secretary general of the United Transport and Allied Union (Utatu), said he rushed to the site to help the train driver and conductor because they were in shock.
"They are currently with the psychologists. You can understand when a train stops after hitting a kombi load of children... .You just see bodies of children lying around.
"It can come back to you four five, 10 years later," he said.
Utatu conducted its own investigation and initial indications were that other cars had already stopped after the booms were lowered, but a minibus taxi came from behind and "zig-zagged" past the booms and over the rails.
"How could this have been prevented, people ask," said de Vos.
"Three or four vehicles had already stopped. The booms went down, but the length of the booms does not stop another vehicle from driving around."
De Vos said the booms only blocked the left side of the road in each direction.
"He (the taxi driver) thought he was still going to take a chance and make it before the train, and people tend to misjudge the speed of a train.
"There are still people who believe that a train driver can reduce speed. It takes about five or six hundred metres, depending on the speed the gradient, for the train to stop."
De Vos said it looked as though the taxi was flung into the air by the impact.
The Railway Safety Regulator said after a preliminary investigation inspectors concluded that a possible mistake on the part of the taxi driver may have caused the crash in Blackheath.
"The flashing lights and booms were found to be in working order. The level crossing is also marked by road signage. This is the maximum level of protection which can be afforded to a level crossing," the regulator said.
"In light of the above measures, preliminary indications point towards possible negligent vehicle driver behaviour at the crossing point."
The taxi was carrying 13 children to school.
ER24 spokesman Andre Visser said there was "total chaos" after the accident.
Police spokesman Colonel Billy Jones said: "While the forensics people were on the scene, they found another child underneath the other children. Those who died were three girls and six boys."
Families and school friends had begun arriving at the crash scene to lay bunches of flowers.
President Jacob Zuma and Transport Minister Sbu Ndebele, who were on a state visit to China, sent a message of condolence to the families of the children. - Sapa