It's a wooden door? Or a metal one? Most likely the hinges or their screws got lose (specially if is a wooden one).
If is made out of iron then they should be welded to the door and frame, not joined by screws.
At any rate, if the door is that heavy you must procure the hinges are appropriated for the weight.
Did it feel like it wasn't opening/closing well recently? You had to force it, felt heavier or once open it keep moving by itself? Or was something out of the blue? If so someone migth have tried to force entry into your place my friend.
The door is a windoor, it can be opened inwards at the top creating a sort of window, or opened regularly as a door, item's glass with a wooden frame. The issue is that it was part of a prefabricated house, which was the last house ever built by the company that built it, because they then went out of business. On top of that, it was an Austrian company, so altogether, it may be amongst the only of its specific kind in the Ireland (maybe a little exaggerated but still) so no-one knew how to fix it when it started opening at the top as a window when you wanted it to open as a door, leaving it hanging on just one hinge, or when it got to the point where you physically could not open it without it going into full window-door mode (which it was almost certainly not made to do) and hanging on one hinge. No-one did anything about it, and eventually that one hinge got tired of holding up a door which was way too heavy for it, and the door hinge committed suicide. And that's the story of why everyone entering the house had to either be lectured on how to open it without putting it one step closer to the grave or just letting someone who already knew how to open it do so for them, until as mentioned, the door hinge deliberately contracted Corona and died. Thank you for coming to my TED talk.