Escape
Shepard knew it had to be the Reapers. They arrived while she was speaking to the committee. It was horrific, watching the Sovereign class Reaper descend from the clouds and start tearing through the streets with its bright red laser. Nobody wanted this day to come. Unfortunately, it did.
Shepard was lucky though. She managed to escape in the Normandy along with James and to her surprise, Kaidan. She ran into him just before meeting with the committee. Upon seeing him, Shepard remembered their fight on Horizon. She preferred not to think of those memories.
It was hard to leave Earth. To leave Anderson behind. She didn't want to leave but the one thing that made it bearable enough for Shepard was knowing Garrus was out there somewhere. She'd find him no matter what.