Getting Old #Horror Story

I was at home getting a little bit bored when I thought I go out and get a part time job for a little extra money and relief from boredom.
The job I got was working for a courier company, one day I had some parcel s to deliver to a block of flats to a Mr Thompson, he was on the 12th floor.
I took the elevator and delivered and knocked on Mr Thompson door he answered, he was happy to see me and guve me a big tip.
As I was leaving I noticed on the door next to Mr Thompson thier was pinned on it a bizarre note.
(Old Man with bad legs ,can't go down to ground floor to put rubbish bags out ,could someone please help me?)
I hesitated for a brief moment, then I remembered that my grandad said it was always kind to help people in need.
So I knocked on the door, it opened to reveal an old man who was at least 80 years of age.
*I saw your note and I would like to help you)I said.
He said (Thank you very much, getting old is very terrible and sometimes very lonely, I just get the rubbish for you)
He invited me in and showed me the rubbish we required to go the waste container down on the ground floor.
It was a small cardboard box sealed with  duct tape and was unnaturally heavy.
He then said out of the blue (Some days I feel better off dead)
I did not wish to participate in such an awkward conversation with him so I just managed to pick up the small cardboard box and make my way to the elevator.
I heard footsteps behind  me it was the old man following me ,he muttered (It was so nice to meet you)
I said (See you again one day)and pushed the button of the elevator for the ground floor with a struggle.
The door closed, I put the heavy box on the elevator floor to give my weary arms and legs a rest, I did think to myself it was odd he said hus legs were so bad he could not use the elevator but he managed to follow me ,perhaps he just wanted to talk to someone.
Suddenly without warning the box hit the  ceiling of the elevator with a loud metallic Clang and the elevator stopped between the 5 th and 6 th floor, the box came down with a heavy thud ,my heart was beating like a fast drum,I could feel my fight or flight human in built reactions almost overwhelming my whole body.
Then out of the corner of my perception of my eyes I noticed a long ,thin cable metal wire which which the box was feeding through a tiny crack in the elevator doors, at this panic set in,the only thing I could think to do was I had to open the box to see inside.
I opened the Box with a biro pen and to my surprise it contained a concrete block with a piano wire wrapped around it ,the elevator then came back to life and when it stopped I came out in a state of horror, so thinking about the old man I rang the police on my mobile phone and just awaited thier arrival.
I later found out when I finally got back home on the local television news that a unknown man body was found with piano wrapped around his neck which was attached to end of a grand piano, this caused his body to be dragged to the elevator and his head was found rolled resting beside it.
I never went back to my part time job,I just spend time in my flat lying in my bed starting at the ceiling slowly but surely going insane with the event that happened, because I am unable to get it out of my head.
Then a voice entered my head.
(Some days I feel better off dead)
At this I got out of my warm comfortable bed waked slowly and calmly to my window, opened the window  placed one leg then the next leg out to the edge, looked down at the ground, and jumped.
My body is now on the ground all my bones broken, blood streaming from my cadaver.