BOSTON (CBS) – Thousands of homes and businesses lost electricity in Medford, Malden, Everett and parts of Melrose Friday morning.

The outage hit a peak of nearly 45,000 customers in Middlesex County around 7 a.m.

According to National Grid, most had their power back within an hour.

There’s still no final word on what caused the outage

The Massachusetts Emergency Management Agency (MEMA) said National Grid had a fault on a transmission line that feeds Medford, Malden and Everett.

However, a National Grid spokesperson told WBZ-TV the utility lost power at seven substations around 6:50 a.m. and the reason for that outage is still not known.

In addition to traffic lights going dark at rush hour, there were also delays on the MBTA’s Orange Line.

Business owners also had problems starting their day.

“No lights, no electricity, so I had to reschedule some of my clients,” Greg Howell, owner of Perfect Style Barber Shop in Malden, told WBZ.

Without power and air conditioning, Howell had to turn customers away.

“It was frustrating because I didn’t know when it would come back on,” he told WBZ-TV’s Susie Steimle. “They said by 11 (a.m.) and it was only 8 o’clock so it kind of got a little frustrating.”

Michael Gaglione, owner of Riviera Auto Body in Everett, says the power outage had little affect on his daily operations but when the lights first went out he was a little worried.

Had the outage lasted all day on a Friday, Gaglione says it would have been “terrible.”

Gaglione said sometimes outages can last two-to-three hours. However, “they did quite well” restoring electricity quickly, he said.