The balloon knocked out the power to hundreds of people in Greenwich over the weekend, according to Eversource

GREENWICH — Eversource is asking residents to take precautions with mylar balloons after one caused a brief power outage in the city early Sunday morning that affected hundreds of residents.

Eversource spokesman Mitch Gross confirmed that about 650 customers lost power between 6 a.m. and 8:30 a.m. after the outage on Milbank Avenue.

“The silver metallic coating on Mylar balloons is a conductor of electricity,” Gross said Monday. “If the ball comes into contact with power lines, it can damage power lines and equipment and cause power outages. In some cases, it could even cause an electrical surge affecting nearby homes.

Stories of balloons causing breakdowns are not uncommon. A California electric utility reported more than 1,000 incidents related to Mylar balloons in a year, CBS News reported.

Gross said people using them as celebrations should secure them with weight so they don’t blow away and should never use metallic tape with a Mylar balloon.

Balloons should also never be tied to a person or child, and should be deflated and disposed of properly once someone is done with them, Gross said.

Finally, never try to remove a balloon entangled in electrical wires.

“Instead, call Eversource at 1-800-286-2000 to report the issue,” Gross said.