I heard on the radio that the bombers had purchased round trip tickets. Now, how they know that is byond me, but, there was speculation that the guys may not have known that they were on suicide missions.
The fourth device failed to detonate at the set time, the fourth bomber was turned away by security, he got on the bus and THEN realized he was NOT in control of the timing mechanism, he going to die and panic set in, but it was too late...
Yeah, the whole bus thing is strange, some reports stated a guy was " fumbling" with his backpack prior to the bus blast. If he "chickened out" or was having second thoughts, why didn't he just ditch the backpack?
"I heard on the radio that the bombers had purchased round trip tickets. Now, how they know that is byond me"
Well the police have CCTV of the bombers at Luton railway station, so I imagine that they can synchronise that with records of tickets sold at that exact time.
It's possible it had a fail-safe that detonated it on any attempt to remove the backpack