Some key NTSB investigators were delayed getting to LaGuardia Airport to start probing Sunday’s deadly runway crash — because they were stuck for hours in painstakingly long TSA security lines caused by the shutdown.

National Transportation Security Board Chairwoman Jennifer Homendy on Monday said her agency was reduced to even having to call one airport to plead with them to let a top prober through the hefty security lines that have been wreaking havoc at airports across the country for weeks.

“Our air traffic control specialist, who was in line with TSA for three hours, until we called — in Houston — to beg, to see if we can get her through, so we can get her here,” she said at a press conference.

“So it’s been a really big challenge to get the entire team here, and they’re still arriving as we speak.”

The crew was still arriving into the early hours Tuesday — despite the crash occurring around 11:40 p.m. Sunday.

“This is our first full day on scene with all of our investigators having arrived up until midnight and 1 a.m.,” Homendy told Fox News’ “Fox & Friends” early Tuesday, acknowledging that she drove herself up from Washington, DC.  

“It has been a really big challenge to get the entire team here.

“I drove up and beat most of our investigators here. They’re coming from all across the nation, and they were in line for hours,” she added.

Massive hours-long security lines have been plaguing airports everywhere, with the delays being blamed on the Democrat-led partial shutdown of the Department of Homeland Security, which has forced roughly 50,000 airport security officers to go without pay for weeks.

Scores of TSA workers have called out after going more than a month without a full paycheck.

President Trump dispatched ICE agents to supplement the missing TSA officers, but wait times at airports across the country are still climbing.

Once they finally manage to arrive on the scene, NTSB investigators will get to work probing the cause of Sunday’s fatal wreckage, which unfolded when an Air Canada jet crashed into a Port Authority fire truck upon landing, killing the pilot and copilot.

Just moments before the collision, an air traffic controller can be heard frantically telling the fire truck, which was racing to the scene of an unrelated emergency, to stop.

Roughly 20 minutes later, the controller appeared to blame himself.

“We were dealing with an emergency earlier,” the controller could be heard saying. “I messed up.”

About 40 passengers and crew members on the regional jet from Montreal, as well as two people from the fire truck, were taken to hospitals.