Power supply in south Mumbai was disrupted on Thursday morning due to a technical fault at Tata Power Company's Trombay plant, a TPC spokesperson said.
"A technical snag in Koyna switchyard of Maharashtra State Electricity Board had affected the Trombay plant, and islanding system could not be employed, leading to power disruption at around 0625 IST," she added.
Only south Mumbai was affected and power connection was restored at 0700 IST, she said.
Meanwhile, railway traffic on both Central and Western lines were affected, throwing train schedules out of gear and affecting office goers.
Local trains were running half-an-hour behind schedule, Railway sources said.