IT consultant David Dixon, 50, died instantaneously after he was caught up in the Brussels terror attack one year ago.
An inquest heard that shortly before the blast Mr Dixon had texted his partner Charlotte Sutcliffe - originally from Creswell - to say he was safe after terrorists had detonated two devices at Brussels airport about an hour earlier.
Mr Dixon, who had lived in Brussels for about 12 years and was on his way to work when he got on the Metro train at Maelbeek station just after 8am on March 22 last year.
The inquest heard CCTV showed the bomber try to board the train’s crowded first carriage.
Hartlepool coroner Malcolm Donnelly said: “Being unable to gain access he made his way to a second carriage, where he entered just before the train moved off, and almost immediately a blast occurred in the second carriage.”
Hearing evidence from a counter terrorism police officer involved in the subsequent investigation, Mr Donnelly said: “The best guess is that Mr Dixon was sitting next to the bomber.”
The officer said: “From our understanding, yes.”
Mr Dixon, from Hartlepool, a father to an eight-year-old son, was the only Briton to die in the co-ordinated attacks, although several others were among the 320 people injured. The attacks killed 32 people in total.
Mr Dixon died of devastating injuries suffered in the blast and was later identified through dental records and DNA.
The bomber used a home-made device packed with nuts and bolts, which Mr Donnelly said was intended to cause ‘maximum damage’ to innocent people.
Mr Donnelley also said photographs of the scene showed carnage and chaos.
Ingredients consistent with the bomb used on the train were found by authorities in a flat used by one of the airport bombers, which the inquest heard described as a bomb-making factory.
The inquest also heard the large criminal investigation into the Brussels attacks is still ongoing.
Mr Donnelly said: “The particular depths of obscenity that people use an ostensible loving God to deliberately kill and maim innocent people is something which is difficult to comprehend.
“The suffering is indiscriminate. Thirty-two people died. There were 320 maimed.”
He added: “Mr Dixon was unlawfully killed clearly, but that doesn’t begin to describe the hurt and the feelings of loss of those that are left behind.”
The inquest was held in Hartlepool on Monday.