More than 20,000 evacuation calls were never delivered to residents in the path of a wildfire that destroyed about 350 homes around Colorado Springs last month, records show.

It was the second time in five months that Colorado residents said they didn't get calls to pack up and run as flames raced toward their homes.

Officials in El Paso and Teller counties were trying to determine why two-thirds of the 32,000 impacted residents did not receive calls during the Waldo Canyon fire that began on June 23.

Nearly 10,000 attempts to reach residents in Colorado Springs were abandoned after the calls were not completed, and more than 11,000 calls were not answered, according to records obtained by KMGH-TV (http://bit.ly/NgfyJT) .

Cassidian Communications, the reverse notification provider, said some calls were not completed because of heavy volume. Phone company officials said their phones were working fine at the time.