A third of Ottawa’s residents on the south side were without power until about 4 a.m. Friday.

The city saw two power outages, one on the north side and one on the south side, caused by a storm packing rain, lightning and strong winds, that struck the Ottawa area early Thursday evening.

Dennis Tharp, director of utilities for Ottawa, said he was unsure of the number of people without power, but noted it was about half of the northern residential area, and about a third of the southern residential area.

The northern side was no problem to restore power, he said.

“That [outage] went back together fairly quickly,” Tharp said. “We were down for about an hour, hour and a half.”

But the southern outage was a little more tricky.

“We had a tree fall on a line at Sixth and Cedar [streets] that took down circuit 12,” he said. “Circuit 12 is again mostly residential — it would’ve had maybe a third of the south side residential out of power. It was quite a mess.”

The tree broke the arms off a pole, and it was “a tight place to work,” Tharp added.

Around 10 p.m., workers split and isolated that particular area to work on it, he said.

“Once we had most everybody back on — except those most directly impacted right there by the problem — it was about 4 a.m.,” Tharp said.

Susan Welte is a Herald staff writer. Email her at swelte@ottawaherald.com.