BALTIMORE (WJZ)– As Southwest’s delays lingered into a second day, they even stranded former governor and presidential candidate Martin O’Malley.

It’s the second computer glitch in less than a year for the airline–which is BWI’s largest carrier and the problems extended beyond the terminal.

Customers were unable to access many of Southwest.com’s functions.

And while the airline was apologetic, it offered no detailed explanation as to what exactly happened.

RELATED: More Than 600 Southwest Flights Delayed, Canceled Due to Computer Outage

Analysts point to the airline’s complicated, overlapping computer systems that are taxed with more functions than ever–from self-bag checks to travel alerts. Even a small problem can magnify, impacting the entire system quickly and airline mergers have made the systems even more complex and the problems bigger.

Paul Dant has extensively researched the vulnerabilities of large computer systems.

“Even a tiny component of that system, that might be critical for the entire thing to work, if it were to go down, you see disruption along these lines,” said Dant, who is a chief strategist with Independent Security Evaluators.

Eighty-percent of all U.S. flights are now controlled by just four carriers–Southwest, United, American, and Delta–which have all reported computer glitches in the past year.

“They’re not required to report those types of things, they’re not required to make public disclosures regarding the nature of a crash, so in most cases, they’re not going to,” said Dant.

Experts say passengers can expect more unexpected cancellations in the future.

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