About 1,500 Entergy New Orleans customers in parts of the Central Business and Warehouse districts were in the dark for several hours Thursday morning following a power outage, a spokesman for the electric company said.

Philip Allison said the outage was reported between 9:20 a.m. and 9:40 a.m.

Crews spent nearly three hours working to restore the outage that left many businesses and hotels in the dark and made stoplights on most of Poydras Street, and several side streets, inoperable.

Allison said utility officials are investigating the exact cause, though it appeared to be the result of equipment failure.

A small fire or smoke was reported at Carondelet and St. Joseph streets in the Warehouse District, but Allison said company officials did not yet know if the fire or smoke started because of the equipment failure or if the equipment failure caused the smoke or fire.

At the Good Shepherd School in the CBD, first-grade teacher Christina Leitz said that in her windowless classroom, the children remained fairly calm when the power went out.

Though one student said he was a little bit scared, Leitz had just downloaded a flashlight app on her smartphone, so they made shadow puppets for a while on the whiteboard.

Since Entergy officials had estimated the power would be out for several hours, she brought the students into a hallway to finish a digestive system science project that used yarn inside of plastic bags for the small intestines.

Power came back on sooner than expected, but Leitz said that when the staff heard that it could be out for the rest of the school day, they started calling parents and sending students home.

The outage happened right as many downtown eateries were getting their late morning breakfast crowds, and as several hotels saw guests preparing to depart.

At Le Pavilion hotel on Poydras Street and a Comfort Inn on Baronne Street, generators kept some lights on.

However, certain non-essential services, such as air conditioning and automated doors, were not working at the Comfort Inn.

At P&G Restaurant and Bar, the power outage ended the breakfast rush early, since diners fled the business as darkness descended, said owner Gus Kouniaris. He said the restaurant typically does brisk business for breakfast and lunch before closing.

The power outage was an annoyance, but Kouniaris said the unexpected is normal in any restaurant.

“You just do the best you can,” he said in the dark and mostly empty business.

Smaller-scale power outages were reported in Algiers after a strong line of thunderstorms moved through the metro area early Thursday afternoon, but Allison said those appeared to be related only to the weather.

Allen Powell II and Kari Dequine Harden contributed to this report.