The graduation was ending, but the problems, well, they were only beginning.

Mere minutes after the final diploma was handed out at Thousand Oaks High School on a June evening in 2019, a metallic balloon released by an attendee floated into nearby power lines — causing a small explosion. It knocked out power to 3,683 homes and businesses and required police to help those leaving the graduation navigate around repair crews.

Fortunately, no one was injured considering the public safety hazards the incident created. Southern California Edison experiences thousands of balloon-caused outages annually — including 1,103 last year. There’s no time worse than during the spring graduation months, with nearly one-third of the outages occurring in May (150) and June (181). As graduation season arrives with more people attending in person, SCE urges those celebrating with metallic balloons never to release them outdoors and always keep them tied to a weight as the state law requires.

“Think about that. In May and June, that’s almost six balloon outages a day,” said Adam Dow, principal manager of Operational Risk Management & Public Safety at SCE. “The safest metallic balloons are tied to a weight or kept indoors, especially during graduation season. These are very preventable outages, and released metallic balloons create unnecessary risks.”

The most significant risk comes when balloons float into electrical equipment and create startling explosions, especially when they bring down power lines — which happened during the Thousand Oaks graduation incident and on 112 occasions last year.

Wire-down situations can potentially lead to severe injuries and even death, as well as fires and property damage. SCE reminds its customers to stay away and call 911 if they ever see downed lines.

However, the most prolific problem caused by released metallic balloons is the disruptive power outages that cost customers 480.6 hours of lost power last year. And, in the graduation incident left about 585 customers without power for nearly 11 hours because of extensive restoration work.

It was revealing for Lori Lyche, a mother attending her daughter’s graduation, who told the Thousand Oaks Acorn, “It happened, and then it was over … I was just surprised a balloon could do that.”

Except it wasn’t over. The explosion was followed by hours of inconvenience to customers, thousands of dollars in repairs and, most worrisome, a public safety threat.

“Metallic balloons look harmless but are dangerous when released outside,” Dow said. “Safety and keeping the lights on are our highest priorities, and we urge our customers to be responsible by, intentionally or unintentionally, never releasing metallic balloons outdoors.”