PSEG Long Island said Wednesday that Tuesday evening’s power outage in Long Beach and nearby areas began with a balloon that wound up tangled in power lines.

PSEG Long Island’s communications director said when the power was switched to another line to remove the balloon, the cable failed - resulting in an outage that lasted around an hour.

Officials said more than 20,000 residents were affected.

Acting Long Beach City Manager Ron Walsh, who is also the city’s police commissioner, said there were four calls for people stuck in elevators. He said they were rescued in about 10–15 minutes.

Katy Tatzel, PSEG Long Island’s director of communications, told News 12 they’re making sure there is a plan in place so this does not happen again. She warned of the dangers of releasing Mylar foil balloons into the air because of the metal on the balloons.

“When it comes in contact with the power line, it can actually cause a short circuit, and that can lead to power outages and fires,” Tatzel said.