Situated in the back of the Sparkle's house was a large domed metal shed that was used as an exterior laboratory for Twilight to conduct experiments in. Hooked up to it was a generator to maintain a constant clean room and eliminate any odors that might have been caused. Unfortunately; the generator had been aging and needed regular maintenance to keep active.
“Not now,” Twilight whined
In front of her were plain bottles with various chemicals that were intended for her latest experiment. Instead of a standard label on them; a simple colored sticker was used as a code that only she could know. A series of bangs resonating from the generator signified it was going out. With nothing left to do; she put the bottles aside and planned to head inside to inform her dad and get his tools to get the generator restarted.
“I really need to start leaving those blasted tools here. It’ll save me from wasting time.”
In the process of Twilight leaving the ‘lab'; her thirteen year old little brother, Spike decided to slip inside and see what she was working on. For some projects that required additional assistance; he was given the role of gofor and told to take detailed notes of everything that was going on.
“What’s it this time,” he thought
“That’s different,” he said in a low voice “What’s in these?”
Picking up one of the containers; its contents were poured into a nearby glass tube, filling it halfway up.
“Thanks dad,” she called “I’ll let you know when I get done.”
“Spike,” she yelled, into a closed door “What are you doing!?”
Hearing her approach startled him as he reached for a second bottle, and grabbed an entirely different one instead. Unfortunately for him, this mistake was about to become disastrous as the two chemicals started to blend together, causing a gas to form.
With the generator currently out of commission; there was no way of pumping out the gas; and the front door had been made to be seal the user inside. Seeing the gas start to emerge; Spike dropped the vial as it turned into solid gas as Twilight ran inside to get her parents and older brother.
“What happened,” Velvet demanded
“I left to go inside and he must have snuck in,” Twilight said quickly
“It’s about to get worse,” Shining said grimly “Gas.”
“Let me in. I have to go,” Twilight pleaded
“Without the generator, the gas can’t be removed and you don’t have a hazmat suit to enter with,” Night Light cautioned
“I’m just supposed to sit here and do nothing!?”
Inside the room; Spike was able to take a look out a nearby window to see his family outside. The gas had quickly started to fill up the room; causing him to start to cough and not see clearly. In this temporary daze; he tried to walk towards the door, but became too disoriented to do so. Whatever he unintentionally mixed had started to further cut off his oxygen as he laid on the floor, on Death’s doorstep.
“Can’t we do anything,” Twilight begged
“Call 911 and tell them it’s a hazardous situation,” Velvet directed
Shining yanked out and phone and punched in the required numbers “I need emergency assistance to the Sparkle residence. Hazardous materials were spilled in the backyard laboratory.”
Nearly ten minutes later; a series of emergency vehicles consisting of half a dozen police cars and an ambulance arrived and were directed to the back. Two firefighters wearing full gear had to break through the safety door as the gas started to dissipate. Once clear; paramedics were able to get a stretcher and collect the now deceased body of Spike.
“My poor baby,” Velvet choked
“This is my fault,” Twilight whispered
“We need get a statement as to what happened,” an incoming officer stated
“This was my fault,” Twilight admitted as the officer started reaching for his handcuffs
“Is that a confession to murder,” the officer asked
“Not like that,” she corrected “I had cleaning products ready in case of spills. When the generator went out; I went to get my dad’s tools when my brother must have entered. For whatever reason, he must have mixed something that was dangerous.”
“She isn’t going to be arrested, right,” Night Light demanded
“An investigation will have to be done along with an autopsy,” the officer explained
Once dismissed from further questioning; Twilight immediately retreated to her room and locked the door. She couldn’t believe what happened and found herself crying into her pillow. Despite any potential recourse from her daughter’s principal, Abacus Cinch; Velvet called the school and notified them that Twilight would not be returning due to private matters that transpired.
Three days later; the final report from the police concluded Spike died of accidental poisoning. The next day the family had a simple ceremony at the cemetery to bury him. Upon their return home, Twilight headed into the lab and grabbed a trashcan and started tossing the bottles of cleaning products inside.
“This is trash,” she muttered “These need to be destroyed…”
With that; she wrapped her arm against a series of glass flasks and threw them to the ground at the same time, resulting in a pile of glass forming. She bent over and grabbed one of the bigger shards and placed that on the table in front of her.
“There’s one last mistake that needs to be fixed.”
Swallowing any fear she might have had; Twilight placed her right arm on the table and held the broken edge to her wrist and drew it across slightly. A small red scratch was starting to form as the shard continued it path.
“Twilight Athena Sparkle,” her mother yelled from the doorway “What do you think you’re doing!?”
“Fixing a big mistake,” Twilight answered, trying to hold back tears “I’d gladly give up my life to fix this.”
“You are not a mistake,” Velvet stated “What do you think your father or brother would do if they heard you killed yourself?”
“This was my fault,” Twilight argued “I need to be punished.”
“Twily; you don’t need to do this,” Shining warned “It’s no one’s fault what happened.”
You didn’t leave the chemicals out! I did! This was my fault!”
“Considering what happened; maybe it’s best we get you to a psychiatrist,” Light offered “But first; let’s get this mess cleaned up and Velvet can clean your wrist.”
“Perhaps we should wait,” Velvet argued
That evening after dinner; the family started watching a movie that had a scene in which a gas canister was used and Twilight started to become pale. She ended up immediately running to the bathroom and threw up. Not thinking much about it; another event happened with her starting to sweat profusely during a war documentary and it was then her parents decided to call a psychiatrist.
“Unfortunately, from what I’ve heard; you might be suffering from PTSD,” Chrysalis diagnosed “My suggestion is to eliminate anything that could trigger another bout. I’d also recommend taking medication to help alleviate symptoms.”
“There is another school we can enroll you in,” Light offered “Your room could also redesigned for just you.”
Taking Chrysalis's advice; the divider was removed from the room and her late brother’s possessions were boxed up and stored in the shed. Despite the thorough cleaning; Twilight could not move anything in the room to the newly created space. They were lucky that the school semester was almost over as Velvet planned to change schools to nearby Canterlot High.
Despite her making friends with six others; she kept much of her personal life to herself, to prevent them from abandoning her if they knew the truth about what happened that day.