Graduations, weddings, and birthdays are all reasons to celebrate, but be sure you're doing so safely. If you're using balloons, keep them indoors. Balloons can break loose from their strings and blow into overhead power lines with one gust of wind, even the balloons are not filled with helium. Mylar balloons are metal-coated and can conduct electricity when they come into contact with power lines. This will cause a short circuit or power surge, leading to large-scale power outages, melted electrical wires, and fires.
If you see a balloon that has made contact with a power line or floated into an electrical substation, never attempt to retrieve it yourself. Keep yourself, your belongings, and all other items and people at least 20 feet away. Call NREMC at 1-888-413-6111 and 911 if there is immediate danger, like a fire or any explosions.