A commuter is fighting for his life after reportedly bending down to pick up his bag and being hit on the head by a rush-hour Tube train as it pulled into a station. Other passengers watched in horror as the man, said to be in his 20s, was struck by a Northern line train at Stockwell station this morning. The station, which also serves the Victoria line, was shut while medics tended to the passenger who was later taken to hospital. Emergency services were called to Stockwell station in south London this morning after a man sustained life-threatening head injuries while bending down to pick up his bag from the platform . Graphic designer Lesia Biloshytska, who was at the station, told how passengers screamed when the young man was hit. She said: 'A girl who witnessed the whole thing said he had been picking up a bag. 'He must have not realised how close he was to the edge as he bent down and his head bowed too far forwards at just the wrong moment. 'I was standing only maybe five metres away and he was hit by the front of the train as it came into the platform. The train was slowing down but we were at the end where people get into the back carriages. 'There were a lot of people on the platform when it happened, and some were screaming. At first we did not know if he was under the train or not.' She added: 'I could only see his legs. I did not see his injuries because staff were gathering around. It was very frightening. 'At this time of morning the platform is always very crowded. You have to let two or three trains go before you get on one and there is sometimes a little pushing with people trying to get on and off.' Commuters told of their shock after witnessing the accident, which happened shortly before 9am today . A man was rushed to hospital after he was hit in the head by a train at Stockwell this morning. File image . Isabelle Zonderland said: 'I was on the tube when it happened. He got hit only metres from our carriage. 'When we were let off the tube I saw him lying there. Someone who I believe was on the platform was checking for a pulse. His face was covered in blood.' Others went on Twitter to tell of what they had seen. One man posted: 'Just saw a poor guy get his head pretty much sliced off by the tube @ stockwell as he bent over to get his bag. Poor guy. Hoping he's ok.' Chris Duncan tweeted: 'Was on this train. Awful. Man hit in the head by oncoming Tube train in horrific accident.' Nick Brown, London Underground's chief operating officer, said: 'A passenger on a Northern line platform was struck by a train entering Stockwell station. 'Our emergency response team and the London Ambulance Service attended the scene. We are investigating the incident to understand exactly what happened but we have already established that while the station was busy, the platform was not overcrowded.' The accident was witnesses by scores of commuters, who told of their horror on Twitter . The London Ambulance Service spokesman said: 'We were called at 8.53am to Stockwell Tube station to reports of an incident. 'We sent an ambulance crew, a paramedic on a motorcycle, duty station officer and London's Air ambulance to the scene. 'We treated a man reported to be in his 20s for head injuries and he was taken as a priority to Kings College hospital.' The accident comes after last month's tragic incident in which Londoner Nick Mann, 35, died of severe head injuries when he attempted to save his 32-year-old brother Robert from being struck by a train at Old Street Tube station. Robert Mann remains in hospital. Earlier in the month, on March 12, a rush-hour passenger was dragged along at Clapham South Tube station - three stops from Stockwell - after getting her coat caught in a train door. The woman ended up falling into the gap between two carriages of the Northern line train and was taken to hospital with serious arm and head injuries.
Man in his twenties said to have bent down to pick up his bag at Stockwell .
He was hit on the head on Northern Line platform of  south London station .
Commuters have said the platforms are too narrow and unsafe when busy .
Man was rushed to hospital with life-threatening head injuries .