Heysel was a horribly tense experience. It remains something of a nightmare.

I was spared the worst excesses because of my presence in a commentary position high up in the main stand. The angle of vision meant I was unable to see the wall collapsing on the extreme left hand side of the ground.

At the very time the match between Liverpool and Juventus was due to start, parts of the old stadium resembled a battle ground.

It was all so different when I arrived in Brussels in the early afternoon. On a bus ride to the venue it was possible to see rival fans enjoying the warm sunny weather, sitting amiably in the roadside cafes and sipping their beer.

It looked like a 'normal' match-day afternoon, although there were later reports of isolated incidents between rival fans in some parts of the city.

Heysel Stadium was arguably best known as an athletics stadium - the Ivo Van Damme meeting was staged here annually. At a time when Europe was blessed with several well-equipped football grounds, the venue for the 1985 European Cup final appeared a puzzling choice.

Its best days were long gone and now it looked like a relic of old decency.

In truth, it was decrepit and this fact was firmly communicated to UEFA by representatives of the two clubs prior to playing on that fateful Wednesday night. Football authorities chose not to listen.

RTÉ's plans for the night were basic by comparison with the standard coverage we are used to in 2015. The late Brendan O'Reilly anchored the programme without any other studio in-put from an expert analyst, and I was on my own commentary-wise at the match.

I was, however, very ably-supported throughout the marathon broadcast by producer Mike Horgan.

One of the first functions you fulfil when working abroad is to make contact with base. This we did about 6.45pm Irish time. I recall telling people in the control room in Dublin that all was well, sun shining still, and a 'minor match' taking place out on the pitch between teams in red and white (roughly the colours of Liverpool and Juventus).

The first inkling of trouble inside the ground came about 7pm.

It is hard to imagine nowadays but the area behind the goal to our left was all terracing, split into corals. As I looked across, Liverpool fans were packed into a section on the right of this terracing, while Juventus followers were located to the left. There were roughly the same number of English and Italians in these two standing areas.

Separating them was a thin corridor of wire meshing, policed by local Belgian officers. In all, I would estimate about 10,000 fans behind this goal.

We can but speculate as to how it all started.

I saw missiles being fired from the Liverpool end over the heads of the police cordon and landing in the Juventus side.

Truly, I was taken aback by this because Liverpool fans always had a great reputation among visiting supporters up to that point.

They were deemed to be good fun, top-class followers, however, on this occasion they had been infiltrated by a hooligan minority that ultimately tarnished the club's reputation.

Panic set in among the Juve followers and they made to move quickly towards the left hand corner of the ground in order to avoid being struck. A crush of bodies ensued. The police looked powerless and unable to restore calm. Gripping fear took hold.

Brendan O'Reilly came on air and led straight to the Heysel Stadium. I should have been giving the latest team news, instead I was trying to find words to match pictures, absolutely unsure of where the unfolding events were going to take me and the viewer.

At about this time the Italian fans fleeing from the violent advances of some in the Liverpool section tried to escape by climbing over a wall. The wall was unable to take the pressure. It collapsed. The scene became a living hell. Bodies were buried under masonry.

We had come to a football match but ended witnessing devastation.

The first 'shots' I had in front of me offered a stark contrast. That whole goal area to the left was utterly chaotic – English fans taunting Italians.

At the other end of the ground Juventus fans waved their flags, seemingly oblivious to the tragedy at the far side. A running track surrounded the pitch, so perhaps their vision was not terribly clear, but some must have been aware that this was more than just a minor incident.

They were becoming witnesses to, and some even participants, in an act of riotous behaviour, which horrified viewers worldwide.

I saw bodies being carried out on to the track by personnel using metal barriers as stretchers. They came one at a time; soon it took on the image of a hospital ward repositioned in a sports ground.

Producer Mike Horgan went away to get some news of casualties and soon came back with word that four people were dead and many more injured. Those at the far end, supporting the Italian champions, soon appreciated the sheer terror affecting their own people. They reacted.

Individual Juve supporters were seen brandishing pieces of metal as they tried to break through the police cordon. Dozens of mounted police officers tried to maintain some semblance of order, but the whole situation seemed quite hopeless. The organisation of the event looked utterly inadequate.

Mike Horgan returned to me again with another slip of paper reading '13 now confirmed dead'. By this stage the Belgian authorities had ordered every available member of their elite riot squad to make his/her way swiftly to the Heysel in the hope that a show of strength might limit the unfolding catastrophe.

Those of us covering the match for our networks throughout Europe had some knowledge of what had transpired, but there were thousands in the crowd of about 58,000 that evening who were largely in the dark. Bear in mind – this was in an era pre-mobile phones and internet.

I was on air for about 40 minutes when the next fatality number given to me read '26', with hundreds injured.

It was the most threatening atmosphere in which I have ever worked, and the question I had at the back of my head was: 'how and when is this thing going to end?'

For long portions of the evening the teams in their dressing rooms were unaware of the full extent of the shocking tragedy. Giovanni Trappatoni was the Juventus manager and Joe Fagan was in charge of Liverpool.

Indeed, that same day came news that Fagan was set to retire after Heysel, with the strong speculation that Kenny Dalglish would succeed him.

About an hour into the broadcast from Heysel the two captains  - Phil Neal and Gaetano Scirea - came to a window in a corner of the stand and appealed to their followers for calm. It was unknown then, but 39 people had just lost their lives on one of sport's most wretched nights.

I'm of the opinion that the two teams would not have wished to play a game of football after all that, if their views were to be sought. However, the biggest fear at that stage in the evening – now about 8.45pm Irish time – was what would happen when hooligans from both groups exited the stadium and confronted one another out on the streets of Brussels? There was enormous trepidation.

The authorities forced the two teams to go out on the park and kick a football. Play the damned final.

I can remember that the first time I relaxed all night was when the match actually started. Dealing with the unknown can be fretful when you are relatively new to sports presentation. Nothing prepares you for [unexpected] pitched warfare.

When the game was over – settled by a Platini penalty for Juve – people left the ground weary, dumbfounded, but surprisingly calm.

Even the 'mad minority' attracted by football's competing macho cultures seemed truly shocked when news of the lives lost in Heysel was revealed. The rest of us got back into buses and were thankful to be able to do so. At least we were among the living.

Thirty-two of the lost lives were Italian, four were from Belgium, two from France and there was one Irishman, Patrick Radcliffe. True, some were made to confront their inadequacies and their guilt in follow-up legal action in the courts, and chief organisers were fired. 

Lessons were to be learned, weren't they? Surely nothing like it could never happen again.  

Four years later, an awful day at Hillsborough proved it could.