LAS VEGAS » Electricity was restored and a major hotel at the heart of the Las Vegas Strip reopened today after a complete blackout and overnight evacuation blamed on damage to the main basement electric line.

The 2,900-room Paris Las Vegas was declared open shortly before daybreak — nearly 20 hours after the hotel, casino, restaurants and shopping areas plunged into what a hotel spokesman called pitch darkness.

“We’re 100 percent open for business,” Caesars Entertainment Corp. spokesman Rich Broome told reporters. “We are not expecting any additional electrical issues going forward.”

About 3,000 guests and gamblers were forced out after the power was cut Thursday morning and a backup source failed to kick in.

Broome said hotel fees were being waived and free stays would be provided for guests who were prevented from returning to their rooms in the 33-story hotel, and to arrivals who had to find another place to stay.

The outage was called an accident — occurring when a worker cut into the power main during authorized and scheduled work in a sub-basement. Hotel and county officials said there was no indication of sabotage or foul play. Broome declined to identify the contractor.

No injuries were reported, but Clark County Fire Chief Greg Cassell said 11 people were rescued from five separate elevators, and a few people suffered from anxiety-related issues. No one was hospitalized, Cassell said.

Power was cut about 9:45 a.m. Thursday. The full evacuation was ordered after noon, when the fire alarm system battery power ran low and backup generators didn’t kick in.

Broome said officials are investigating why auxiliary power didn’t function as expected.

As night fell, the iconic faux Eiffel Tower lit up, but the hotel remained dark and authorities decided it was too late to promise to let guests back in. Only people who needed prescription medication were escorted by hotel and security officials to their rooms.

Entrances to the hotel were draped in yellow crime scene tape and firefighters went door-to-door inside the darkened building to make sure everyone was out, the fire chief said.

The outage drew comparisons to an Easter Sunday 2004 blackout that lasted three days at the 3,000-room Bellagio resort across Las Vegas Boulevard. Business losses in that case were estimated in the millions of dollars.

Broome said estimates of the loss due to Thursday’s outage weren’t immediately known.