On Monday, I worked from 8am until 6pm as a surgery sister at Stepping Hill hospital in Stockport. I was in bed that night listening to BBC Radio Four when I heard the words ‘Manchester’ and ‘incident’. I immediately thought about Declan, my son, a student who lives in central Manchester. I shot downstairs, spoke to my husband Sean. We rang Declan and established that he was OK, then I rang work and went in.

When I got there at 1.30am there were ambulances outside which had brought in six of the 59 casualties from the arena. They were stabilised in the A&E unit and brought to the surgical department where I work. They all had what we call lower limb injuries with foreign bodies – shrapnel injuries. Metal bolts and nuts, some an inch wide, had gone into them. They had caused real damage and left big holes in people. Shrapnel is like a large bullethole. It just destroys anything it goes through – arteries, bones, nerves, the lot. I’ve been in operating theatres since 1988 and it’s the most upsetting thing I’ve ever seen.

My patient was a lovely, lovely lady who had been in the foyer of the arena when the bomb went off. She had extensive, horrendous injuries caused by the shrapnel, including broken bones and tissue damage. She was in theatre from 3am until about 6.30am. I talked to her just before she went to sleep for the operation and she was just holding my hand and saying ‘Thank you, thank you’. She was in a very bad way but was still smiling and saying thank you. That showed real humanity; I thought that was amazing.

At least four of the six patients needed surgery. Usually only one of our 18 theatres is open overnight for emergencies. But on Monday, surgery was going on simultaneously in three of them, staffed by teams including about 25 other colleagues who like me had just come in to help – surgeons, anaesthetists, nurses, theatre technicians, radiologists to read X-rays and hospital managers – everyone.

Surgeons took the bolts and nuts out of patients and repaired the damage they had caused. One woman with abdominal shrapnel damage who arrived at 4am ended up in theatre for 12 hours.

The atmosphere in the surgical department overnight was very calm and focused but also very emotional. I found it emotional partly because of my lovely lady patient, who didn’t deserve what happened to her; I’ll always remember her smiling. And emotional also because one of the doctors I worked with overnight had actually been at the arena when the bomb exploded, waiting to pick up his daughter from the concert. He didn’t even mention that though. I don’t know how he found the strength to come into work and work all night after getting his daughter home, and after being at the scene of such horror, but he did. I said to him, ‘You’re fantastic.’ But he just said: ‘I’m not fantastic; it’s what we do.’

Strangely, it was only when the police told us to bag up the clothes belonging to the casualties and also the shrapnel – not to clean the bolts and nuts, because they would need them for evidence – that I realised something awful had happened. That brought home the enormity of it.

I’m still feeling very raw and emotional. I finally finished at 9.30 on Tuesday morning and I cried when I got home. On the BBC news a lady was appealing for help to find her daughter and that reminded me of how I felt when I woke up and panicked about my son in Manchester. I cuddled up with my black labrador, called Shadow, on the floor and had a good cry.

A terrible thing happened, and there’s no explanation for it. But I don’t want to think about who did it. I want to focus on the good I saw and was part of on Monday night. We should focus on the love and warmth people displayed after the bomb, and on those who helped those affected, like the homeless guys who gave people directions after the bomb, and not on those who do things like this.