[JURIST] The top auditor for the US Department of Transportation says that holiday travel disruptions at US Airways and Comair have prompted a formal investigation into customer service commitments made by the airlines five years ago. Many passengers were left stranded in airports or separated from their baggage this weekend while carriers blamed poor weather, computer breakdowns, and staff shortages. Lawmakers had threatened stricter congressional regulations in 1999 in the wake of high-profile incidents of customers stuck in delayed aircraft. The DOT Inspector General said this would be the first step in a major audit of the entire airline industry's customer service. The Transportation Department's General Counsel and its Office of Aviation and International Affairs are also taking part in the probe. The DOT has released this statement from Secretary Norman Mineta and this response from the Inspector General laying out the terms of the probe. Reuters has more.