DETROIT (AP) — Detroit officials say power is gradually being restored to government buildings, schools and other facilities after a major cable failure caused parts of the city to go dark.

Local officials say electricity had been restored to about a third of the customers served by Detroit's public lighting department by mid-afternoon Tuesday.

Mayor Mike Duggan says the power grid hasn't been modernized in decades in Detroit, which is emerging from the largest municipal bankruptcy in U.S. history. DTE Energy Co. is taking over the department and upgrading the system.

The outages prompted Detroit Public Schools and Wayne State University to dismiss students early. Other affected facilities include Joe Louis Arena, home of the Detroit Red Wings.

Service also was suspended by the Detroit People Mover, an elevated rail line looping downtown.