SOWETO, South Africa, May 20 (UPI) -- A metro train crashed into a stationary train in Soweto, South Africa, injuring at least 644 passengers, two of them critically, officials said.
Witnesses said Train 9432 hit the back of a Business Express train between the Mzimhlophe and Phomolong stations Thursday, the Cape Argus in Cape Town reported.
The critically injured passengers were airlifted to a Johannesburg hospital.
Dozens of paramedics from across the region were sent to the accident scene but passengers and witnesses said some people waited hours to be seen by emergency medical personnel, the Cape Argus said.
Metrorail Chief Executive Officer Mosenngwa Mofi said investigators would determine whether the crash was as a result of human error or structural failure.
Mofi said the Metrorail's infrastructure was "aged and prone to errors."
