- Video report by ITV News Correspondent Paul Davies
A teenager accused of planting a bomb on a tube that partially exploded at Parsons Green station planned a "lethal attack", a court heard.
Ahmed Hassan, 18, is charged with attempted murder and using the chemical compound TATP to cause an explosion that was likely to endanger life. He denies the charges.
Hassan, of Cavendish Road, Sunbury, Surrey, is said to have used Amazon and Asda to research and buy ingredients for an improvised explosive device (IED) that partially exploded injuring 30 commuters.
The Iraqi-born teenager is said to have prepared the attack while his foster parents were away on holiday between September 1 and September 8 last year.
Jurors were told the bucket containing the bomb was loaded with shrapnel designed to be propelled out during the explosion to cause "maximum harm and carnage".
He allegedly used a £20 voucher he won for being 'student of the year' to buy a key ingredient of TATP, the Old Bailey heard.
Opening the trial, prosecutor Alison Morgan told the jury that just before 8.20am on September 15, an IED partially detonated on a district line shortly after it arrived at Parsons Green Station.
She added that there were 93 people in the carriage when the bomb exploded.
Ms Morgan said: "The partial explosion created a large fireball. Some in the carriage were caught by the flames and sustained significant burns.
"Many ran in fear and panic.
"They were fortunate. Had the device fully detonated, it is inevitable that serious injury and significant damage would have been caused within the carriage.
"Those in close proximity to the device may well have been killed."
She added: "The prosecution allege that in constructing and detonating a device of this type, made of approximately 400g of TATP and loaded with metal shrapnel, the defendant intended to kill people.
"The consequences of detonating a device of that type are obvious and are magnified by the presence of shrapnel.
"The prosecution therefore alleges that the defendant intended that this should be a lethal attack."
CCTV played to the jury of the incident showed a large fireball engulfing the carriage and people ducking from the flames.
The court heard that Hassan was not among the hundreds of people who fled from the Tube and down a narrow staircase, as he had got off a station earlier, at Putney Bridge.
Ms Morgan said: "He never intended to be injured by the device himself.
"Instead he had created a timer system to ensure that it detonated in his absence."
Jurors were shown images and graphics of the device and how this was constructed.
- A white plastic bucket with a Lidl plastic bag inside it, covered with a dark fabric and a pair of trousers.
- A tupperware container with a lid, covered in foil, at the bottom of the bucket. This contained around 300g of the volatile explosive triacetone triperoxide - TATP.
- A blue glass vase containing approximately 100g of TATP.
- Around 2.2kg of shrapnel made up of sockets, screws, bolts, nails, knives and screwdrivers which were in the bucket, but not in the container.
Hassan allegedly used Amazon to research how he might source hydrogen peroxide - one of the key ingredients he needed for the TATP to make his device.
On August 26, last year, he also looked at the uses of hydrochloric acid, jurors were told.
He later created a new gmail email address which he used to buy five litres of hydrogen peroxide at 11% which he purchased using a £20 Amazon voucher he won at Brooklands College in Surrey for being "student of the year", the court heard.
On September 3 Hassan is alleged to have purchased 98% sulphuric acid from Amazon.
The court was told that during the explosion an improvised initiator was expelled from the bucket.
It was made up of a modified electric timer, a bulb with wires attached and a 9V battery.
The initiator was connected to the timer, which resulted in the explosion.
Jurors heard details of the injuries suffered by people on the train, which included burns to their faces and bodies.
One woman said she could smell herself burning and could see that her hair was on fire.
Some were also injured in the stampede as people ran from the scene in panic.
Hassan arrived in the UK in October 2015 and claimed asylum after travelling through the Channel Tunnel on a lorry with no identity documents.
Jurors heard he gave his name as Ahmed Hassan Mohammed Ali, and said that he was born in Iraq on June 1, 1999.
The court was told he was given accommodation and by the middle of 2016 was living with foster parents in Sunbury.
The trial, expected to last two weeks, continues.