The violent storms that ravaged the New Orleans area two weeks ago knocked out both power lines into Louis Armstrong International Airport, and problems with the electrical system prevented airport officials from powering the entire terminal even after one of those lines was repaired, a New Orleans City Council committee was told Tuesday.

That meant that while most airlines had power restored to their concourses within an hour after the airport was forced to switch to emergency generators April 27, the portion of the airport serving Southwest Airlines — the airport’s largest carrier — remained without commercial electricity for six hours, Aviation Director Iftikhar Ahmad said.

About 68 flights were delayed and 59 were canceled because of the storm, though Ahmad said those decisions were made by the airlines and not by the airport.

“There were no safety issues. The airport never closed, but some airlines did choose to cancel their flights,” he said. “That’s not our policy; that’s their policy.”

The airport is fed by two lines from Entergy Louisiana. One of those feeders provides power to all four concourses at the terminal.

The other line, which was repaired within an hour after power went out at the airport, has been connected only to concourses C and D since January, when crews tested the electrical system and found problems that prevented that line from being used to power the whole terminal.

That meant power could not be supplied to Concourse B, which is used by Southwest Airlines, until Entergy crews fixed the second line. The other 14 airlines that use the airport use concourses C and D.

A walnut tree had fallen on that line and it took about six hours to restore power, said Melonie Stewart, with Entergy Louisiana.

The only similar occurrence in the past five years was when the airport lost power during Hurricane Isaac in 2012, Ahmad said.

After the outage, emergency generators at the airport continued to provide power for exit lights, safety lighting, security systems and other safety features, airport spokeswoman Michelle Wilcut said.

Providing additional generators at the airport would increase costs. Rather than looking at major upgrades to the existing terminal, officials said, they are focused on the new half-billion-dollar North Terminal project, which is expected to be completed in 2018.

One element of that project that has been proposed — but not yet funded — is a solar array that would be able to provide power to the airport even if it lost commercial power.

Follow Jeff Adelson on Twitter, @jadelson.