A timeline of the London bomb attacks as they unfolded on Thursday, July 7, 2005:

3:48 a.m. -- Blue Nissan Micra rented by Shehzad Tanweer, 22, also believed to be carrying Mohammad Sidique Khan, 30, and Hasib Hussain, 18, seen on video camera outside Leeds, 300 kilometers (185 miles) north of London.

5:47 a.m. -- Red Fiat Brava driven by Germaine Lindsay, 19, arrives at railway station car park in Luton, 50 kilometers (30 miles) north of London.

6:40 a.m. -- Tanweer, Khan and Hussain arrive at car park; all four men put on large rucksacks and enter Luton station minutes later.

7:40 a.m. -- The four board train for London.

8:23 a.m. -- Train arrives at King's Cross station in London.

8:30 a.m. -- Video camera captures the four hugging and looking happy before splitting up.

8:51 a.m. -- Nearly simultaneous explosions on three Underground trains.

8:52 a.m. -- London Underground system reports a series of power surges.

8:55 a.m. -- Hussain seen on Euston Road, outside King's Cross station; phone records show he tried to contact his three companions.

9:00 a.m. -- Hussain enters shop at King's Cross station and appears to buy a nine-volt battery.

9:06 a.m. -- Hussain goes into McDonald's on Euston Road, stays about 10 minutes.

9:19 a.m. -- Man fitting Hussain's description seen on No. 91 bus going from King's Cross to nearby Euston station. It is believed that he switched to a No. 30 double-decker bus at Euston, taking a seat at the rear of the upper deck.

9:29 a.m. -- Metropolitan Police confirm "major incident" in London.

9:47 a.m. -- Explosion on No. 30 bus.

12:55 p.m. -- Home Secretary Charles Clarke informs House of Commons there have been four explosions on the transport system.

4:35 p.m. -- The Union Jack at Buckingham Palace is lowered to half staff.

10:19 p.m. -- Hussain's family contact Casualty Bureau, reporting him missing.

11:40 p.m. -- Police find items identifiable as belonging to Khan and Tanweer at scene of one explosion.