Iris, I'm sorry wasn't able to get your laptop back
It's okay Barry, but you shouldn't have just ran after him like that, you could have gotten really hurt.
Whoo hoo! I can run fast now!
One day, Barry was so happy to see the Particle Accelerator turn on, but he's best friend, Iris had her laptop stolen and Barry tried to run after him, But He unfortunately couldn't catch up to the thief and had missed the Accelerator turning on, So Barry had decided to had to go to his lab at the CCPD.
He was looking at the results but then he saw that the Particle Accelerator exploded. He looks out the window and a wave of energy goes outward toward the Police Station, so Barry goes to close the overhead window when he is struck by lightning and thrown towards a rack of chemicals.
9 Months later, Barry wakes up from a coma and is in some laboratory, and then realizes that it's Star Labs. Later that day he finds out he has super speed, and would be later known as... The Flash!