Survivors of the Croydon tram crash, in which at least seven passengers died, have spoken about the scenes of horror inside the blood-soaked carriages.
Martin Bamford, 30, was on his way to work when the tram "flipped" at 6.13am near Sandilands tram stop.
He told how a girl, who "did not look very much alive", ended up on top of him after the crash.
Bamford, a gutter cleaner from South London, claimed the driver said he had "blacked out" before the crash.
"When we were coming through the tunnel we were going at some speed and the tram was speeding up more and more," Bamford said.
"We were coming out of the tunnel and we hit the bend way too fast and the tram flipped. It was extremely frightening, people were screaming and shouting for help.
"The tram was full mainly of people going to work. There was a girl who was on top of me and she did not look very much alive at all.
"She was bleeding all over the place and I don't think she made it. People had broken legs and head injuries.
"When it flipped everything went flying, people were on top of me.
"There was blood everywhere and belongings and shoes. It was absolute carnage.
"I just can't seem to get it out of my head, it just keeps going over and over again."
The British Transport Police said this evening that the 42-year-old male driver, from Beckenham, was arrested on suspicion of manslaughter.
Residents said the vehicle was coming down towards a bend on a steep slope and carried on down the hill rather than turning, it then tipped over onto its side at the entrance of a tunnel.
Several survivors were trapped in the wreckage, with a large team of emergency workers battling for hours to free them and ferry the dozens of injured to hospitals across the capital.
Bamford added the crash was "like something out of a movie".
"I looked around and there was just blood everywhere I was shouting through to the driver to ask him if he was okay," he said.
"He was laying on his side and I asked him if he was ok. I think he was in his mid 30s or 40s.
"There was another woman next to me who I think was okay, I pulled the emergency door handle but it didn't work, the doors wouldn't open. I was shouting at the driver to open the doors.
"It was like something out of a movie, you just wouldn't expect it."
Another survivor, Rhys McCausland, 19, described the terrifying moment he was thrown across the carriage and his head was crushed against the ground as the tram windows smashed behind him.
It was a normal morning for Rhys, who was headed to work from New Addington.
He said: "I didn't notice we were coming to a corner because I wasn't really paying attention. The next thing I knew the tram was rolling over on its side. There was no attempt to brake or anything like that.
"I rolled on my back. The glass has smashed behind me and my face rolled over the gravel. I was quite lucky not to be trapped like the others.
"There were people flying towards us and bags flying everywhere. It was quite dark at the time and it was still raining.
"At first we didn't know if we were still in the tunnel and we wanted to find a way out. There was no escape from the tram on its side.
"I was in shock. I could feel blood pouring down the side of my face, but I was quite lucky it wasn't worse. I could feel the blood dripping and I was in total shock about what happened.
The chef, who works at Westminster, was treated for a deep gash to his head.
The Rail Accident Investigation Branch said the tram derailed as it was negotiating a "sharp, left-hand curve" with a speed limit of 12 mph. A spokesman said: "Initial indications suggest that the tram was travelling at a significantly higher speed than is permitted."
Kudirat Okesola, 46, rushed to her husband's side as soon as she heard he had been caught up in the crash.
Taiye Ajibola, who was on his way to work, was "very anxious", Okesola said, adding that there was a lot of blood.
"Even my husband was covered with blood," she said.
Ms Okesola said some people were trapped underneath the tram calling for help.
"People were screaming. People were crying," she said.
She said her husband has a "massive" cut on his face.
The Croydon Health Services NHS Trust said the "vast majority" of people have been discharged from the hospital or transferred elsewhere for ongoing care.
The Wimbledon-bound tram, one of the first services of the morning, was travelling from New Addington.
Local people have raised concerns about speeds at the corner where the carriages derailed.
Pat Rooke, 72, a nearby resident, described the scene in the wake of the incident as "pandemonium".
He added: "They (some trams) do come around that corner very fast sometimes, and it is quite a sharp bend."
Sue Patel, who lives near the station, said: "I heard a noise at around 6 o'clock and I thought maybe it was a car or something. But then I saw there were helicopters."
She described the sound as "very loud" and a "very big bang".
Patel, who said she regularly takes the tram line, said: "There's quite a big bend. You come through the tunnel and there's quite a sharp bend."
A passenger on a tram told how, less than a fortnight ago, he was left shaking as it travelled through the same area.
Andy Nias wrote on Facebook that he and 29 fellow travellers feared the worst when their tram "took the hard corner to Sandilands at 40mph".
He added: "I swear the tram lifted onto one side."
Wednesday's crash is believed to be the first tram crash involving fatalities on board since 1959, when two women passengers and the driver died after a tram caught fire in Shettleston Road, Glasgow, following a collision with a lorry.