Earl’s Court station has been evacuated due to a reported emergency.
Transport for London said the Tube station had been closed “due to a customer incident”.
Pictures on social media showed an air ambulance landing nearby.
Commuters described chaos as the gates to the station were closed and it took around 10 minutes to get out.
“People were pouring out of trains onto the platforms but it was so crowded no one could move,” Harriet Hall, a journalist at The Independent, said.
“We all moved slowly out of the station. It took about 10 minutes to actually get out, partly because there were so many of us, but also the gates remained closed which slowed things down significantly. Then firemen ran past shouting for people to let them through.”
She added: “It was mayhem. If it was a terror incident nobody would have been able to get out.”
The London Fire Brigade confirmed they had sent two fire engines and a fire rescue unit to the scene.
A spokeswoman said: “We were called at 8.51am to reports of a person on the track. We’ve got two fire engines and a fire rescue unit in attendance.”
No action by firefighters was required, she added, and the brigade stood down at 9.15am.
The British Transport Police said the station had been closed after “concerns for the welfare of a person on the tracks”.
A spokesperson said: “Officers attended alongside the colleagues from the London Ambulance Service, and a person was taken to a place of safety.”
The London Ambulance Service said: “We sent an ambulance crew to the scene. We treated a man and took him to hospital.”
The station reopened around 9.25am.
