Josh Hilliard, a baker at Wheatfields Bakery, 904 Vt., uses a head lamp from his bike kit to help see in the dark, as a power outage left most of downtown Lawrence without electricity Monday morning.

Westar Energy is still investigating the cause of the first of two power outages in Lawrence that affected thousands of customers Monday.

The first outage cut power to more than 7,700 customers from 9:30 a.m. until about 10:45 a.m. The power failure was centered primarily in an area northeast of 23rd and Iowa streets. Nick Bundy, a Westar spokesman, said the outage occurred because of damage to a major power line. However, it’s still unclear exactly what damaged the line. Bundy said, “It’s probable it was lightning.”

The second outage, caused by a fallen tree, began about 12:30 p.m. and left more than 1,700 customers without power for about 20 minutes. The outage affected an area bounded by 20th Street, Louisiana Street, 23rd Street and Stewart Avenue.

Area businesses shut down for portions of the day.

“With the power out, as many things, you’re pretty well dead in the water, I guess,” said Jason Climer, shop foreman at D&D Tire, 1000 Vt.

Workers milled around the shop Monday morning, waiting for the power to come back on. “Without electricity, you have no air compressors or anything,” Climer said.

A few blocks away, Wheatfields Bakery employee Josh Hilliard found a creative way to work.

“I grabbed my head lamp out of my bike tool kit,” he said. “This is the first time I’ve needed to use it. I’m glad because it’s a real pain to try to bake without an oven light.”

Over at Lawrence Memorial Hospital, emergency generators kept the hospital running smoothly, said Jeff Novorr, LMH vice president.

“No patient care areas were without electricity,” said Novorr, though the hospital operated with some of its nonessential lighting off.

When the lights popped back on, it was a relief.

“When it goes out, you never know if it’s going to be for 30 seconds or an hour or more. … The lights are shining again, so everything’s back to normal,” he said.