Cinergy spokesman Steve Brash said the company received about 100 calls from customers saying they smelled gas in Avondale, Mount Auburn, Evanston and Walnut Hills in Cincinnati, and Bromley and Bellevue in Northern Kentucky.

"We have found no gas leak," Brash said.

Cincinnati fire officials said they also had at least 30 reports of a natural-gas smell but found nothing.

Cinergy crews checked out each report after receiving calls, from 7 to 10:20 a.m., Brash said.

The company isn't sure what caused the smell but has ruled out leaking gas, Brash said. "It was over a widespread area. For it to have been a gas leak, it would have had to be a very large and consequently identifiable leak."