"Several people were found walking around on the scene while some were found still seated inside the taxi," ER24 spokesperson Russel Meiring said in a statement.
"Upon closer inspection, paramedics found one man lying trapped inside the front seat of the taxi." Meiring said the Provincial Fire Services had to utilise specialised rescue equipment to free the man from the taxi.
"Once the man had been freed, paramedics assessed the man and found that he had sustained numerous injuries and was in a serious condition."
The remaining thirteen patients had sustained injuries ranging from minor to moderate.
The injured patients were treated and the seriously injured man was provided with advanced life support interventions, before they were all transported to Letaba Provincial Hospital for further medical care.
"It is believed that the driver lost control of the taxi, causing it to veer off the road and crash into the tree," Meiring said.
Local authorities will be launching an investigation into the exact cause of the collision.