HONOLULU (HawaiiNewsNow) - For HECO, those metallic balloons with celebratory messages are no party.
In fact, this year alone, they've been blamed for 21 power outages on Oahu. That's up from previous years.
When the balloons get loose and float into overhead power lines, they can cause a short circuit and knock out power to an entire neighborhood.
In the latest incident on Sunday, Hawaiian Electric Co. officials said, a metallic balloon got tangled in power lines on Waialae Avenue. More than 1,200 customers lost power.
Since 2008, there's been average of 17 metallic balloon outages annually (though there were 26 in 2013).
To avoid the outages, HECO is asking partygoers to secure the balloons snugly or weight them down. And after the party, don't release them -- deflate them.