According to Metro officials the downtown-to-Pasadena section was without electricity because an overhead power line fell near Elysian Park.
Buses bridged the gap in the line, transferring passengers to the next working platform. By 9 a.m. trains were again running on the entire Gold Line.
The power problems meant trains had to share a single track on part of the line, meaning the normal Sunday schedule of one train every 12 minutes was reduced to one train every 20 minutes. Metro officials say to expect delays throughout Sunday.
City News Service contributed to this story.