A new documentary will show the moment Westminster terrorist Khalid Masood arrived by stretcher at a London hospital coping with the immediate aftermath of the attack.Five people died in the rampage, which saw Masood drive at pedestrians on Westminster Bridge before fatally stabbing Pc Keith Palmer in the grounds of the Palace of Westminster.The 52-year-old attacker was then shot by armed police and was the first casualty to arrive at St Mary’s Hospital in Paddington, where he was pronounced dead.A camera crew filming series two of the BBC Two documentary Hospital were at St Mary’s on March 22 and captured the fatally wounded Masood being stretchered in. Shortly after his arrival, a member of staff is heard saying: “The first one is RIP.”The episode also tracks the progress of three people injured during the attack – two French teenagers on a school trip, and a 40-year-old British man who was on a birthday excursion in the capital. All non-emergency surgery is cancelled, and doctors must decide which existing patients are well enough to be transferred to another hospital to free up beds.Dr Alison Sanders, clinical director at Imperial College Healthcare NHS Trust, said: “When a major incident happens, within 12 minutes the entire hospital has kicked into a completely different way of working, and obviously, subsequently we’ve had to do that twice more since this programme was made (with the London Bridge attack and the Grenfell Tower fire). “It just demonstrates, that’s something that won’t be unique to us, it’s a countrywide ability of the NHS to step up on top of what is already huge pressure.”She added: “We have to do something entirely different with zero notice, and you see everybody just switch into it, and then the following day we have to go back to normal because the work is still building up, the ambulances will still be coming in, as soon as we open the doors again, the floodgates open.”The first episode of Hospital series two airs on BBC Two on Tuesday June 20 The Hospital camera crew were just two or three days into recording the new series, which follows the Imperial College Healthcare Trust, when a meeting being filmed at St Mary’s was interrupted by news of the attack.Staff at the hospital, one of London’s “major trauma centres”, are seen quickly putting a major incident plan into place as they prepare to receive the first casualties. Simon Dickson of programme maker Label1, said of the decision to include the attacker: “He’s part of the story, and his appearance in the film is as you see it.”It’s brief, but his arrival is a key part of the day, and that is fully reflected in the way that scene is handled.” Masood’s family were not consulted about showing him, and his face is blurred out in the footage.BBC Two controller Patrick Holland said: “The decision was made to treat him in exactly the same way, from the point of view of the hospital.”That’s where we’re seeing him, that’s where the audience is being allowed to see this incident unfold, he’s the first casualty that comes to the hospital and we followed the same protocol that we do with any other patient which is that if they don’t consent, you blur them.” Want the best of The Telegraph direct to your email and WhatsApp? Sign up to our free twice-daily Front Page newsletter and new audio briefings.