A jury has been shown CCTV footage of the moment a huge fireball engulfed a packed District Line tube last year.
Panicked commuters could be seen cowering from the bright flames that filled the packed carriage before rushing out of the train at Parsons Green station in west London on September 15 2017.
Ahmed Hassan, 18, is on trial at the Old Bailey accused of planting the bomb.
The jury was shown CCTV footage of Hassan the day before the attack allegedly buying shrapnel for the bomb from Asda in Feltham, before cycling to Aldi.
Detective Constable Andrew Leonard told the court the Asda receipt was later recovered and showed that he bought matches, a screwdriver bit set and batteries.
Jurors were told the batteries could have been used for the bomb timer. The court also heard evidence from several people injured in the blast, giving harrowing accounts of their ordeals.
One woman, known only as Miss S, gave evidence from behind a screen and said she had been horribly scarred and burnt.
Through tears she described hearing the bomb, seeing a giant flame and then realising her body and clothes were burning.
Hassan has denied attempted murder and using the chemical compound TATP to cause an explosion that was likely to endanger life.
The trial continues tomorrow.