The incident happened at 6:22 a.m. on the 6200 block of Rhode Island Avenue, where the bus careened off the road and into the structure.
The driver was rushed to the hospital in critical condition, according to authorities.
Four passengers were aboard the bus at the time of the crash but were unharmed. Emergency crews responded swiftly to the scene, and no other injuries were reported.
The cause of the medical emergency remains under investigation.
Officials are assessing the damage to the building, which was unoccupied at the time of the crash.
This is a developing story. Check Daily Voice for updates.
Want breaking news in the DMV as it happens, or want to contribute? Join the DMV All Incidents Facebook group.
Click here to follow Daily Voice Olney and receive free news updates.