A mother and child who accidentally fell on to a Tube track moments before a train arrived escaped unhurt by moving into a pit under the track.
Police said the woman was pushing a buggy along a platform at Baker Street station in London on Friday night as she checked the arrivals board.
Distracted, she veered too close to the edge and fell down.
The father jumped down to help and the three of them moved into a pit beneath the track as a train passed over them.
None of them was seriously hurt, but they were taken to hospital for checks, British Transport Police (BTP) said.
The incident happened on the Jubilee Line, on the southbound strip of platform seven, TfL said.
BTP said an investigation was "continuing" into the exact circumstances of what happened.
Peter Holland said he saw people screaming and running in tears following the incident.
"We got to the platforms at Baker Street just as this happened, the train whistling, people screaming and running in tears", he said.
"I can't tell you how relieved I am to hear this wasn't fatal. Thoughts out to the driver of the train. Unbelievable."
A woman who was at Baker Street described how the platform was quickly evacuated.
"I was on the platform for about two minutes and then an alarm went off which said 'this is an emergency. Everyone leave the station'," she said.
"I left the station and within five minutes there were fire engines, police cars, St John's Ambulance, British Transport Police and undercover police cars.
"I saw a man leave the station with a child, then a woman came out and she was wearing white trainers which had black skid marks on, and then someone brought a buggy out of the station, but it didn't look damaged."
You may also be interested in:
Commuters who also witnessed the incident at 22:15 BST took to social media to record their shock.
One user said: "Thankfully all unharmed. The driver is also ok and he did a superb job, along with a chap from the depot that was on his way to work. What a night."
When pushchair with kids and mum end up on the track in front of the train you were just about to board. 😔 Thankfully all unharmed. The driver is also ok and he did a superb job, along with a chap from the depot that was on his way to work. What a night.— 3.1 / アン (@version3point1) September 7, 2018
Another witness expressed her concern for the family to Transport for London.
Can you confirm if the people involved are ok ? I saw the incident and am very concerned— Josie Harvey (@Josieharveyy) September 7, 2018
Nigel Holness, director of network operations at TfL said: "We are relieved that the family who were involved in the incident at Baker Street last night were able to escape unharmed and we offer them our best wishes.
"Having reviewed footage from our platform cameras and spoken to those involved we understand this incident was an accident but it does underline the need for all customers to remain behind the yellow line when waiting for trains or walking along the platform."