Updated 8:15 PM ET
Thousands of fliers across the U.S. were delayed Friday afterclosed parts of the airport. The prolonged shutdown at the nation's third largest airport was particularly troublesome for those hoping to head to the East Coast or across the Pacific Ocean.
Flights bound for Los Angeles that had not yet taken off were held at their gates for hours by the Federal Aviation Administration. The so-called ground stop was in effect until around 4 p.m. PDT. Nearly 200 flights were canceled. Some flights already in the air were allowed to land at LAX, while others diverted to nearby airports.
Gina Marie Lindsey, executive director of Los Angeles World Airports, which operates the Los Angeles airport, said Friday afternoon that 746 flights nationwide were affected by the incident. Some 46 were diverted, and others were held at LAX or at the originating airport.
Flight tracking site FlightAware.com said that as of 3:30 p.m. PDT, 195 flights to and from LAX were canceled and another 268 were delayed. To put that in perspective, there were roughly 200 other flight cancellations nationwide Friday, mostly in New York and Philadelphia because of rain and wind.
Some passengers who landed at LAX after the shooting spent at least two hours sitting on planes parked in a remote corner of the airport.
Even though the airport never fully closed, travelers trying to fly out were unable to reach it because of massive road closures.
Lindsey said it will take "quite a deal of time" to get operations back to normal. She said it will be a "carefully orchestrated logistical ballet."
LAX's Terminal 3, where the shooting occurred, remained closed Friday evening as the forensics investigation continued.
A man carrying a note that said he wanted to "kill TSA" pulled a semi-automatic rifle from a bag around 9:20 a.m. local time and shot his way past a security checkpoint. One Transportation Security Administration officer was killed and at least three other were wounded, authorities said.
One security expert doubted much could be done to prevent similar incidents.
"I am not sure what can be done other than effectively banning most types of guns as in the U.K. where there are minimal shootings," said Kenneth J. Button, a public policy professor and director of the Center for Transportation, Policy, Operations and Logistics at George Mason University.
"This could just as well happened on a street in New York or at a shopping mall," Button said in an email in which he also alluded to last year's mass shootings in a Colorado movie theater and at a Connecticut elementary school. He added that "airports are possibly one of the safest places given the security there."
Los Angles is a major gateway for flights to Asia, Australia and New Zealand. Domestically, the largest cities served are San Francisco, Las Vegas, New York, San Jose, Calif., San Diego and Phoenix.
However, it is not a major connection point such as Chicago, Atlanta, Dallas and Minneapolis.
Most airlines issued waivers for people traveling through Los Angeles, allowing them to change flights without paying a fee.
JetBlue diverted flights from Boston, New York and Fort Lauderdale, Fla., to nearby Long Beach airport. Southwest Airlines diverted at least one flight - a trip from Chicago that landed in Denver.
Officials at Sky Harbor International Airport in Phoenix said seven flights to Los Angeles were canceled, including five on Southwest. Seven flights from Sky Harbor to LAX were delayed and 10 flights headed to Los Angeles from elsewhere were diverted to Sky Harbor.