SAN FRANCISCO -- Almost 2,000 customers were briefly without power Saturday after an advertising banner being towed by an airplane fell to the ground.
The banner caught on power lines over the intersection of Fifth and Brannan streets, near Interstate 280, around 11:48 a.m., according to San Francisco fire Capt. Tony Dumont. No one was injured.
The outage affected about 1,980 PG&E customers, according to spokesman J.D. Guidi. By 1:15 p.m., that number was down to about to 250. There was no estimated time for full restoration of service, he said.
Photos on Twitter and various local media showed that the ad was advertising an "8.99 haircut sale."
The Federal Aviation Administration regulates the aerial advertising business and has launched an investigation, said spokesman Ian Gregor.
"All aircraft operations have to be conducted so they don't pose a hazard to any people or property on the ground, and we would want to know what caused a banner to come off a plane in flight," he said in an e-mail.
FAA investigators spoke to San Francisco police who said the single-engine plane towing the banner was registered to Ad-Viation, a San Ramon-based company. A call to its offices Saturday was not immediately returned.
"Police told us that the banner towing Stinson biplane ... released its banner under unknown circumstances," Gregor said.
Justin Jaye, who runs FlySigns.com and has been in the aerial advertising business for 23 years, said he could not recall a time when an ad banner had fallen to the ground -- without the plane falling with it.
"I've never had one just cut loose and drop," said Jaye, who manufactures signs for use across the country, including in the Bay Area. He said his company had not made or flown the haircut-sale banner that fell on San Francisco on Saturday.