At the height of the storm Wednesday night into Thursday, which ripped trees from the ground and pummeled areas with tennis-ball-sized hail, roughly 7,000 Montana-Dakota Utilities customers in Bismarck-Mandan were without power between 12:30 a.m. and 4:30 a.m.

Mark Hanson, MDU spokesman, said those 7,000 customers were split almost evenly between the two cities.

Roughly half of Mandan was without power in the western third and southern half of town for about an hour when a substation had to be shut down, said Hanson.

All main lines have been repaired, Hanson said, but as of 4 p.m. Thursday, about 50 customers in the two cities were still without power.

Hanson said those still without power are from individual power lines to houses or businesses that are likely the result of severed branches or fallen trees.

He said he talked to workers in the field who said they planned on working into the evening, because what's left has to be done on a case by case basis.

In addition to the inconvenience of no power and keeping electricians busy all Thursday, it also kept police and firefighters busy early Thursday morning.

Between 2:30 a.m. and 3 a.m., Bismarck police had calls reporting downed trees, trees in power lines, power lines down, small fires and various alarms all across town, said Sgt. Dwight Offerman of Bismarck police.

"They were pretty busy," Offerman said.

Mandan police also responded to numerous alarm calls caused by the power going on and off, said Sgt. Jay Gruebele of the Mandan police.

Bismarck Fire Chief Joel Boespflug, said they responded to 11 emergencies, all about the same time. He said there were a few small fires, but nothing serious and all were extinguished without major damage.

If someone sees a down line, Hanson said they should not to go near it or try to remove branches from any lines, because they could still be charged. He said to call MDU and let them handle the problem.

Contact MDU by calling 800-MDU-FAST (800-638-3278)

(Reach reporter Chris Rosacker at 250-8254 or at chris.rosacker@bismarcktribune.com. Jenny Michael contributed to this story.)