Disclaimer: I do not own Transformers, this is purely for shits and giggles. No sueing me, thank you.
Optimus Prime drove, he didn't stop at the main gates or even slow down; he sped up to crash through the flimsy metal fencing placed around them by the human military. He didn't know why they would even bother with such a thing but figured that it must have something to do with their fragile psyche. With their need to keep things in order and restrain that which they do not understand. It pained him to know that even though they had just fought side by side, both the humans and the Autobots lost friends.
Ignoring the repeated inquires from his teammates he kept going, building more and more speed until he was exceeding the speed limit that had been posted and exceeding the speed limit for the human trucks that he had assumed the form of. He needed to get away from it all. The death of Jazz was weighing heavily on his spark, he was the one responsible for his death. And while Ratchet had tried numerous times to convince him otherwise he had been unsuccessful.
Could it be that if he hadn't stopped to deal with Bonecrusher that he might have been able to save Jazz, to prevent the death of his second in command? But if he hadn't paused to deal with Bonecrusher then which one of them would have? Would any of them paused to deal with the Decepticon threat? Ironhide surely would have given pause had Optimus himself not paused to do so. But then great Weapons Specialist would not have been able to aid Sam in fleeing with the All Spark.
He was the only one among them who could have possibly dealt with the great behemoth on the highway. Which meant that Jazz was meant to die. No, he wasn't meant to die, he was foolish having attempted to fight Megatron by himself.
Optimus could recall quite clearly the first time that he had fought along side the wise-cracking Cybertronian. It had been a pivotal fight for them all, Tyger Pax, where young Bumblebee had been attacked by Optimus' brother. Megatron. Jazz had proved to be invaluable, increasing the fire power and giving aid when he could despite his diminutive size. Jazz was quite lucky then to have escaped with the rest of them, they were all lucky to have gotten away from the quick-to-attack Decepticons.
Jazz might have been small but his courage was large, he had a spark as strong as Ironhide's. A true fighter. All of them. Optimus knew that Jazz might have given him a relatively hard time when he assigned them foes; always giving him the smallest of them. It was for his own good, much like the way he paired Bumblebee and Ratchet together during fights. They had lost a great comrade on Earth; but in hindsight they had gained valuable new ones as well.
The human adolescence, Sam Witwickey, proved to have more courage than them all. Willing to risk his life for them, much like the way that he was willing to die for the sake of Earth's safety. Why didn't the human boy do as he asked and put the Cube into his spark. He knew that Megatron would have survived and most likely destroyed the planet in the aftermath of his anger but his comrades could have dealt with him.
No, he thought, they would not have been able to defeat Megatron on their own. His power was equal to Prime's own power.
Optimus Prime skidded to a stop at the bluff, his front tires millimeters from going over the edge of the cliff face. With a sigh that sounded a lot more like a revving of his engines he peered over the edge at the waters below. This world was simple, plain and had little to offer them in the way of energy but it needed their protection now more than ever.
He allowed thoughts to wash over his processor, reliving memories from Cybertron and of his, their, time on the Ark.
"I am sorry Jazz."
Although he knew that it was impossible for his friend to reply he could hear Jazz's voice echoing in his mind, "What for, Prime?"
"I have failed you all."
"You have always been too hard on yourself, Optimus," rumbling up on either side of the Detroit Diesel, Ratchet and Ironhide expressed their own opinions of his actions at Mission City.
"Thank you both reminding me of my duties."