What would be the most pleasant form of euthanasia?

In Wagner’s estimation, it takes 13 milliseconds for the brain to process information from the eye, a hundred milliseconds to feel pain. But 13 milliseconds into the implosion, there is nothing left intact of the cylindrical section of the Titan.

“They would have been dead ten milliseconds ago,” says Wagner. “They wouldn’t really feel anything or see anything coming. They would just be instantly dead

Source

Between the first crack and them dying was a fraction of a second

Whatever it was, I'll lay good odds it probably felt far too long...