Palo Alto is considering filing a complaint with the Federal Communications Commission after its emergency dispatch center was flooded with 566 automated calls over a five-hour stretch in mid-January.

Dispatch Center Director Charles Cullen said dispatch received 566 calls during within five hours between Jan. 13 and Jan. 14. In each case, the dispatchers did not hear anything from the other end.

The calls did not significantly disrupt dispatch operations, he said.

"We were fortunate that it wasn't a really busy time," Cullen said. "It was somewhat disruptive to our operations but it didn't jeopardize our ability to respond."

Records indicated the calls came from a Verizon cell tower. Though the city is still looking into exactly what caused the calls, police officials believe they were caused by a device that automatically dials 911 from a vehicle when a crash occurs.

The device is manufactured by Continental Automotive Group, Cullen said. The city has requested more information from Verizon and from Continental, he said.

Cullen said other manufacturers, such as OnStar, create mobile devices that first verify the crash before calling the dispatcher -- a model that he said makes technical glitches much less likely.

Cullen, a board member of the state chapter of the National Emergency Number Association, said his organization has expressed concerns about such auto-dial devices in the past.

"Anything that auto-dials 911 has potential for technical failure, as happened here," Cullen said. "We'd like to see a different model used."

He said a similar technical glitch occurred in Vallejo a few days ago. In that case, the city received between 1,000 and 2,000 calls within hours, he said.