A luxury train carrying more than 50 foreign tourists derailed Wednesday in Pretoria, South Africa, killing two people, including a pregnant woman, an official for the train line said.
Rovos Rail train manager Joe Mathala told CNN the accident occurred when the train - which runs weekly from Cape Town to Pretoria - stopped to change engines from electric to steam for the rest of its journey.
"While we were waiting for the steam train, the locomotive started moving by itself," traveling 17 kilometers (10.5 miles) downhill before it derailed, "toppling coaches over one another," Mathala said. The two women killed were workers on the train's kitchen staff, Mathala said.
Seven passengers were seriously injured, he said.
The train was carrying 40 American tourists, two New Zealanders, four Brits, four Frenchmen, three Germans and five South Africans, according to officials. Of the 40 Americans, 10 were receiving medical treatment at a hospital, the U.S. Embassy said in a statement.
"Our thoughts and prayers are with the people impacted by this accident," said U.S. Ambassador Donald H. Gips. "We want to thank the South African emergency response and others who assisted immediately, and we will continue working closely with South African authorities to help the affected Americans."
- CNN's Nkepile Mabuse contributed to this report.