"It partially detonated, it had a large quantity of explosive and it was packed with shrapnel". The Metropolitan Police force said Hassan is charged with attempting to "murder persons traveling on a District Line train" and of using a chemical compound known as TATP to cause an explosion likely to endanger life. He was arrested on September 16 at the English port of Dover while trying to board a ferry to France. A number of other searches have been completed, police said.
The attack sparked a huge hunt for the perpetrators and prompted officials to briefly raise the national terrorism threat to the highest level, "critical". "So, it could have been so much worse", Dick told LBC, a London-based talk radio station.
Two others - a 48-year-old identified as D, and a 21-year-old identified as B - were released from police custody on September 21, with no further action.
Six men were arrested in connection with the bombing.
One of those released is a 21-year-old, originally from Syria, detained outside a fast-food restaurant in west London on Saturday.
Three men aged 17, 25 and 30 remain in police custody in connection with the investigation with searches still taking place at addresses in Surrey and Newport, Wales.
Elsewhere in her interview, Dick downplayed the extent to which terror attacks in London and elsewhere are co-ordinated, despite that fact that ISIS has repeatedly claimed responsibility for them.