The Mane Six (now subsequently the Mane Five) were never the same since that tragic day. Ponyville itself seemed to be covered in a long shroud of darkness that sucked everything into it's void.
Rainbow Dash never spoke after the day of the funeral. Nor did she ever do any work as a weather pony. Something inside her snapped that day. All she did any more was lay on the highest cloud she could possibly find and look out into the distance or sleep.She was now just a hollow shell of what was once Rainbow Dash.
Fluttershy never left her cottage again. Her anxiety had gotten so terrible she feared that merely walking out of her house would lead to her being hurt or killed. She cried much more often than she used to and over the smallest things. She eventually wouldn't eat any longer.
Applejack returned to her life at Sweet Apple Acres. Though she wouldn't admit it, something had definitely changed within her. She was a lot colder than she used to be and she would snap frequently. She didn't talk much and preferred to be alone in the orchard. And no matter how brave a face she put on, she couldn't hide the fact that a large part of her had been buried along with Twilight.
Rarity was always somber and very depressed. She would have frequent spells of tears and melodrama to avoid thinking about how much the loss had effected her. She became a workaholic and would spend weeks, sometimes months, behind a locked door working on dresses that were mediocre compared to the eloquent, flashy, and absolutely astonishing ones they had previously been.
Pinkie Pie had sunk to an all new low. She would rarely exit her room and when she did she would be prone to fits of madness, similar to schizophrenia. She became very bitter and harsh towards others. Instead of taking pride in seeing smiling faces, she was jealous of them. She felt that if she couldn't be happy nopony else should be either.
Celestia, Luna, and Cadence continued their royal duties. Celestia became almost mechanical. She seemed to no longer have any emotion and be seemingly almost apathetic towards the rest of her kingdom at times. Luna slept all day and worked all day, never speaking to anypony. Finally, Cadence spent her time trying to spread as much love as her weak heart would allow.
The lesson they all learned was the suicide is never an answer and this effects every pony in an entire kingdom. It leaves almost nopony untouched. And they all silently vowed to never let another event like this happen again.