(CNN) -- The impact of Friday's shooting at Los Angeles International Airport is still being felt by the nation's air travelers.
The Federal Aviation Administration announced it ordered a first-tier ground stop that ended at 3 p.m. PT (6 p.m. ET). The ground stop applied to LAX-bound flights that were departing from airports in the western United States; those aircraft were held at their departure airports, the FAA said in a statement.
Nearly 750 flights were affected, with 46 flight diversions, according to Gina Marie Lindsey, executive director of Los Angeles World Airports.
Flight tracking site Flightaware.com reported 104 departures canceled and 93 arrivals canceled out of the 1,114 flights that were scheduled to operate at LAX after 9:30 a.m.
On Friday morning, at about 9:20 a.m. PT (12:20 p.m. ET) a gunman opened fire at a Transportation Security Administration checkpoint. One TSA officer was killed and two others were injured.
The airport was in the process of letting employees back into Terminals 1 and 2 around 4 p.m. PT Friday, Lindsey, said. Terminal 3, where the incident occurred, will remain closed for the time being, Lindsey said. Passengers expecting to fly out of Terminal 3 should contact their airlines for more information, she said.
Many travelers took the delays in stride. Some stuck in airplanes at LAX took to Twitter to document their delays, but the tone was largely respectful.
"First time I have been to LA in years and have been on Tarmac for 2 hrs due to Lax shooting. Prayers go out to all victims," wrote @joeycorrado.