Bus controllers were not told there had been explosions on three Tube trains before a fourth bomb went off on a bus, the inquest into the 7/7 attacks heard today.
The bombing of a number 30 bus in Tavistock Square, central London, came nearly an hour after the atrocities on the London Underground on July 7, 2005.
Tube managers passed only limited information about the earlier blasts on to their colleagues running the capital's bus network, the hearing was told.
The families of some of the 13 people killed in the Tavistock Square bombing have questioned why London's entire public transport network was not shut down after the Underground attacks.
Andrew Barr, London Underground's network co-ordination manager, was questioned today about communications between the Tube's network control centre (NCC) and Centrecom, the control room responsible for London's buses, on the day of the bombings.
Hugo Keith QC, counsel to the inquest, said to him: "There isn't very much in terms of the information received from the NCC as to what your thinking was as to the possible cause of the explosions.
"Because they weren't aware until the bomb detonated in Tavistock Square of the explosions."
The inquest also heard that nearly all London Underground's planning for a terrorist incident was based on a single attack.
Mr Barr said: "My previous experience over 20-plus years had been single point attacks at various locations, and indeed we had actually had them."
Shortly before the July 7 atrocities Tube managers took part in a training exercise with the Metropolitan Police looking at how to respond to multiple attacks, as happened in the 2004 Madrid bombings.
Underground bosses were considering how to implement the lessons of this operation when the suicide bombers struck the capital.
Mr Barr said: "I have a planning team of about 10 people and we started to look at what the key issues were for this exact point.
"Regrettably, before we had a chance to put that in, these events overtook us."
Islamic terrorists Mohammed Sidique Khan, 30, Shehzad Tanweer, 22, and Jermaine Lindsay, 19, detonated their devices in co-ordinated attacks on three Tube trains within three minutes of 8.50am.
London Underground's control room issued a "Code Amber" at about 9.18am ordering all Tube drivers to continue to the next station platform and stop.
The entire Tube network was completely evacuated at around 9.40am.
The last time a network-wide Code Amber was used was in December 1991, when Irish republicans attacked a number of London Underground depots, the inquest heard.
Many Tube workers complained after July 7 that they were not told what was going on, the hearing was told.
One member of staff said they found out more about the attacks by switching on the television than by calling the NCC.
Mr Keith suggested that Tube controllers were hampered by communications difficulties on the day of the bombings.
He asked: "Would you agree, Mr Barr, that on the morning of July 7 the flow of information to the NCC did not work as well as you might perhaps have expected?"
The senior Tube manager replied: "It was not as good as it should have been."
He added: "In the first 30 minutes or so, there was so much information coming in that all of us were in possession of a variety of information, and I'm not sure if we shared adequately."
Mr Barr also agreed that NCC staff were "overwhelmed by the sheer number of calls", some of which they were not able to answer at all.
He defended London Underground's delay in confirming that the Tube explosions were caused by terrorist bombs.
"Until we actually know, our experience is it's far better to deal with the precaution, far better to deal with the evacuation of customers, rather than sending out a sort of estimate of what we believe the issues are," he said.
The inquest heard there were significant gaps in the information received by Tube controllers on July 7.
For example, British Transport Police inspector Robert Munn told his control room at 9.19am that he saw "bomb damage" on a Tube train targeted at Aldgate station but this did not get through to Mr Barr, the hearing was told.
The coroner, Lady Justice Hallett, said: "It sounds as if London Underground weren't sufficiently in the loop for the emergency services procedure."
Mr Barr agreed: "I think that's fair."
Mr Barr said he was concerned to establish an accurate picture of what happened in the immediate aftermath of the Tube explosions.
He told the inquest: "It would be easy to hypothesise, it would be easy to try and guess.
"The penalties for getting it badly wrong were fairly catastrophic for our customers."
Crucial help would have been diverted if London Underground had repeated incorrect reports that Liverpool Street was one of the stations targeted in the attacks, the hearing was told.
"There was a risk of the dilution further of the very scarce resources that we had," Mr Barr said.