(CNN) -- Here's a look at what you need to know about the terrorist bombings on July 7, 2005 in London, England, which killed 52 people and injured more than 700.
Timeline: (all times listed are British Summer Time) July 7, 2005
8:50 am - Three suicide bombings occur within 50 seconds of each other on three different trains traveling through London Underground stations. The locations targeted are:
- A train just outside the Liverpool Street station, killing seven people.
- A train just outside the Edgware Road station, killing six people.
- A train traveling between King's Cross and Russell Square stations, killing 26 people.
9:15 am - The system is shut down as British Transport Police confirm an explosion near London's financial district in the area of Liverpool railway station.
9:27 am - Metronet, the subway maintenance company, says a power surge has caused an explosion in the London tube station.
9:47 am - The fourth suicide bomb explodes on a double-decker bus at Tavistock Place, killing 13 people.
9:53 am - Metronet says the entire London subway network has been shut down. Incidents are reported at the Aldgate station near the Liverpool Street railway terminal, Edgware Road and Kings Cross in north London, Old Street in the financial district and Russell Square in central London.
10:25 am - Police confirm an explosion on a bus in central London in the area around Russell Square.
11:07 am - News agencies report all bus services have been suspended in London.
11:15 am - European Union Commissioner for Justice and Security Affairs Franco Frattini tells reporters in Rome that the blasts in London are terrorist attacks.
12:00 pm - British Prime Minister Tony Blair declares in a public statement the "barbaric" London blasts are terrorist attacks and were designed to coincide with the G8 summit in Scotland.
12:35 pm - Scotland Yard revises the number of blasts down to four, three in the underground system and one on a bus. Originally, there were thought to be six separate attacks.
July 13, 2005 - Three of the four suicide bombers are identified as Shahzad Tanweer (Aldgate), Hasib Hussain (Tavistock Square), and Mohammed Sadique Khan (Edgeware Road).
July 14, 2005 - The fourth bomber is identified as Germain Morris Lindsay, responsible for the King's Cross/Russell Square attack.
July 28, 2005 - CNN reports that more than a dozen unexploded bombs were found in a car at Luton station in north London five days after the attack.
September 1, 2005 - Al Jazeera airs a videotape of Mohammed Sidique Khan calling Osama bin Laden, Ayman al-Zawahiri and Abu Musab al-Zarqawi "today's heroes."
September 16, 2005 - Police search homes and businesses in northern England in connection with the bombings, but make no arrests.
May 11, 2006 - The British government releases two reports, concluding the bombers acted without the assistance of foreign terrorists.
March 22, 2007 - Three men are arrested in connection with the attack. Two are arrested at Manchester Airport, where they are preparing to catch a plan to Pakistan. The third man is arrested at a house in Leeds. The three men are arrested on suspicion of the commission, preparation, or instigation of acts of terrorism under the Terrorism Act 2000.
April 5, 2007 - The men are charged with unlawfully and maliciously conspiring with the four suicide bombers and of conspiring to cause explosions at tourist attractions in London. They are identified by British police as Mohammed Shakil, Sadeer Saleem, and Waheed Ali.
August 2, 2008 - A mistrial is declared after the jury fails to reach a verdict.
April 28, 2009 - At the re-trial, Ali, Shakil, and Saleem are found not guilty in helping to plan the attack. Ali and Shakil are convicted of conspiracy in connection with pre-attack reconnaissance missions and receive seven year sentences the next day.
May 6, 2011 - A British coroner report is released clearing the emergency services of failing to respond quickly enough to the bombings. Justice Heather Hallett rules that the severity of their injuries meant each of them would have died, no matter how quickly help reached them. In the wake of the suicide bombings there were claims that police and firefighters had been unwilling to get close to the scenes of the blasts because of safety fears.
April 30, 2012 - Internal al Qaeda documents surface providing details that British-subject and al Qaeda operative Rashid Rauf planned the 2005 London bombings carried out by groups led by Mohammed Siddique Khan on July 7 and Muktar Said Ibrahimon July 21.