This is part of the Railroad quest "Butcher’s Bill".
In the ground floor, there's an Advanced floor safe in the room to the SW and Protectron pod in a small room to the south.
There's an armor and weapon workbenches, book return terminal in the main hall. Navigate your way around the hospital until you reach the main raider stronghold composed of makeshift shacks and wooden bridges around within the hospitals’ several floors. From the ground entrance, you have to take an elevator to reach it. It’s the only way to get up so don’t worry about getting lost.
The second blue door to the right can be opened using the Novice terminal beside it. However the doorway’s blocked so you can’t go through here anyway. Head to the main hall and kill all the enemies there. Once done, go upstairs to the NE corner and make your way to the elevator.
After leaving the elevator, follow the path and destroy the turret in the second corner then go down the ramp. Follow the path around until you reach blue double-door. You’ll find a large hall with lots of makeshift wooden structures made by the raiders. Follow the quest marker and it will Lead you to a desk with a note “Augusta Station Last Update”.
With no way of getting back from where you came from, you have no choice but to continue down to the bottom floor. There’s an active generator with fusion core in the hospital’s generator room. There is also a deathclaw here so be careful. You have to activate the circuit breaker in the southern corner of the room to Power up the security door.
The corridor past the security door is highly irradiated. The first room to the right has a green steamer trunk. Follow the corridor and exit through the door leading back to Cambridge.