Knocking on the door

One day, while sitting on the armchair, relaxing and watching the show, a knock was heard on the door.
Nothing unusual, it happens all the time.
For example, the knock could be heard, when the mailman bringing the letters, and bills, or the delivery of a package, sometimes I even get some prank knocks from the kids in the neighbourhood.
Usually it is the neighbours knocking on the door, due to my dogs making “too much noise”.
Since it’s nothing short of a recurring event, my body moved by its own, but when my bottom was barely lifted from the armchair, I froze.
I started sweating, and trembling, and everything in my body told me to stop, and ignore the knocking.
The knocking continued in the same slow rhythm.
Knock-knock-knock 3 seconds of pause, then knock-knock-knock again.
I felt the urge to go to the bathroom, also, it was on the other side of the house, further away from the knock.
The moment I stepped out of the room, a portion of the roof fell right in between the armchair and the door.
“If I had walked to the door, I would’ve been hit!”
I thought to myself.
Thinking about the door, I realised that the knocking sounds stopped.
I thought that maybe the loud boom scared away whoever it was at the door.
It’s been 65 years since then, and now I am an old man at the age of 93.
I had a long life, with a beautiful wife, smart kids, and plenty of grandkids to play with.
I was watching the TV once more, thinking that tomorrow my kids will visit me.
But right then, a knock was heard on the door.
This time although, I smiled, I wasn’t young anymore, and could feel clearly who came looking for me.
I closed my eyes, and waited, drifting away with the sounds of the knocks.
Knock-knock-knock 3 seconds of pause, then knock-knock-knock again.