ALTON – An overnight fire in Alton is under investigation.

It happened before 11:00 p.m. Wednesday at a building near Mile 5 and Conway in Alton.

Fire investigators said the fire started in an apartment on the top floor.

No one was there at the time and officials said they haven’t been able to locate the person who lives there.

No one was hurt.

Officials are still working to determine the cause of the fire.