National Transportation Safety Board officials said they're aware that there are "a lot of questions" and "a lot of debris" investigators need to sift through in the aftermath of the deadly collision between an Air Canada airplane and a firetruck at LaGuardia Airport.

Chairwoman Jennifer Homendy explained during a Monday evening news brief that the NTSB is an independent federal agency charged by Congress to investigate civil aviation accidents in the United States as well as significant events in other modes of transportation.

She stressed that the NTSB is not part of the U.S. Department of Transportation, which gives the NTSB oversight authority of investigation over the Federal Aviation Administration.

Homendy said the CRJ900 aircraft was operated by Jazz Aviation, doing business as Air Canada Express. She says Flight 8646 collided with a fire rescue truck as the plane landed on Runway 4 around 11:37 p.m. Sunday. The airplane had 72 passengers and four crew members on board. Two firefighters were in the firetruck.

Homendy said five members of NTSB's Transportation Disaster Assistance Team are on scene, as well as the chief of the Transportation Disaster Assistance Division. They work in concert with the American Red Cross to provide resources and information about the investigation, as well as what NTSB is doing, to those who lost loved ones, survivors and their families as they move through the investigation.

She said she expects to have 25 specialists on scene, in addition to the other NTSB employees.

Homendy said the team arrived Monday at 3:10 a.m. Some were still en route as of Monday evening.

Homendy said she understands that there are a lot of questions that many are hoping for answers to.

She said LaGuardia was shut down, there was a ground stop order at Newark Liberty International and there were long Transportation Security Administration lines.

Homendy explained that the NTSB has an air traffic control specialist who was in a TSA line for three hours until they called Houston to beg to get her through in order to get her to LaGuardia.

She added that it's been a challenge to get the team to LaGuardia. The latest she expects the rest of the team to arrive is on Tuesday around 1 a.m.

Many NTSB members have arrived by small planes, some by train and some drove up from Washington, D.C.

Homendy said investigators also did a walking inspection of the scene. A site commander also did a safety walk of the scene to ensure investigators were safe.

She said there is "a tremendous amount of debris" from Taxiway Delta across Runway 4 to some other areas, as well as hazardous materials on the firetruck.

Because the plane's tail is on the ground, Homendy said Port Authority and emergency responders had to cut a hole in the roof of the plane in order to get to the Flight Data Recorder (FDR) and the Cockpit Voice Recorder (CVR). Crews got the recorders for the NTSB investigator who drove back to the lab in D.C. to verify that the CVR was not damaged. Homendy said they will begin work on FDR on Tuesday.

Homendy hopes to have more information to share on that on Tuesday in another press conference.

She said investigators will collect information from the FAA and others on air traffic control staffing in the tower and communications training.

Investigators will look for information on the fire and rescue department, on their crew and their vehicle, as well as the capabilities of their vehicle, how much they weighed and what they were carrying.

Homendy said the NTSB already has an operations group formed that will look at the operator itself, as well as procedures and training for the aircraft.

The NTSB will have a system's investigative group that will examine the components of the airplane's hydraulic, electrical and navigational, pneumatic and associated systems, including instruments and flight control systems.

The NTSB also has a structures group that will document the airframe wreckage and accident scene, including calculating impact angles.

Homendy also said that there is an air traffic control investigative group, as well as a CVR group and FDR group. The NTSB will have an airport operations and survival factors combined group. That team will look at airport rescue and firefighting operations at LaGuardia and will look at injuries that the plane passengers sustained in relation to the dynamics of the crash.

Homendy said they have already collected surveillance video, but asked the FAA for the Airport Surface Detection Equipment (ASDE). The ASDE will provide a replay of the event, essentially the display that was provided to the air traffic controller. The team will look at that to determine where the aircraft was at times and whether the firetruck was visible.

The NTSB will also get an ASDE analysis from the FAA's tech center that will provide information on whether alerts were generated and other data, including the distance of the aircraft that was landing on Runway 4 as the firetruck was approaching the runway from Taxiway Delta.

Homendy said that the NTSB has a lot of information on staffing, but emphasized that the NTSB deals in facts. She said the NTSB doesn't speculate, doesn't take one person at their word, and is determined to verify information before the agency provides it.

Homendy said the NTSB could not provide information on air traffic control staffing and the experience of the pilots as of Monday night. She said information needs to be verified by looking at records and signing sheets. She said the agency also has to do interviews and look at time cards and official records from the airline.

As far as where the plane and firetruck were when air traffic control gave clearance, Homendy said investigators will have to get that information from the FDR as well as the ASDE analysis.

She said investigators need to have the CVR verified and analyzed to determine if the pilots followed directions. They also need to determine the shifts of air traffic controllers as to when they began their shift and when there was a transition.

Homendy said investigators will also look into what protocols exist between airport operations with respect to firefighting and aircraft landing during the investigation.

Homendy said that it's going to be some time before Runway 4 is reopened, emphasizing the amount of debris on the runway. She said investigators have to determine what to take back to the lab in D.C., what they want to collect and take pictures of, and what to document.

The NTSB will work with the Transportation Safety Board of Canada. Homendy said they'll have technical advisors with them from the operator and manufacturer as well.

Homendy also said the air traffic controller would typically be removed from duty following an incident. She said they'll interview the air traffic controller on duty, those who were in the tower, as well as those who weren't.

The NTSB brief followed an earlier news conference by Transportation Secretary Sean Duffy and Federal Aviation Administrator Bryan Bedford at the airport.

Duffy and Bedford were joined by Kathryn Garcia, executive director of the Port Authority, Gov. Kathy Hochul and Mayor Zohran Mamdani.

Bedford said they have been in contact with Air Canada and Jazz Aviation. He added that weather conditions at the time of the crash were moderate but that there was mist and fog. He said the Port Authority firetruck was responding to a situation on a United Airlines plane when the collision occurred.

Bedford stressed that the FAA is fully committed to the NTSB in the investigation.

Garcia said the Port Authority works with its partners to ensure the safety of passengers. She said that the collision was the first fatal incident in 34 years at LaGuardia.

She said a fire crewman was expected to be released later on Monday, while another will remain for observation.

Garcia said the airport reopened to passengers at 5:30 a.m. and the first flight departed after 2 p.m.

Hochul conveyed condolences and said that her administration is cognizant of the impact the collision had on LaGuardia and Port Authority.

She vowed that New York state will offer its full cooperation in the investigation.

Mamdani thanked partners in the state and federal government for their help.

He praised crews for their quick response to the scene, as well as passengers who took action to help others who were impacted.

Mamdani said that Air Canada set up a hotline so that people can get in contact with loved ones who may have been involved in the incident.

Mamdani said his team will continue to share new information as they get it.

Duffy added that when incidents like these happen, politics fade away and people come together.

Duffy said that he's heard a rumor that there was only one controller in the tower, but said that this is not accurate.

He briefly addressed staffing at LaGuardia and said that there are 33 air traffic controllers at the airport and seven in training. He said the target number for LaGuardia is 37.

Duffy said LaGuardia is well staffed, but still faces shortages only by a couple of people.

Duffy also pointed out that here is a lag time between training of air traffic controllers and when they are fully operational.

He also said that air traffic controllers who are about to retire are asked not to do so, and they're offered a 20% bump in pay so that they will stay.

Duffy said the FAA has great working relationship with NTSB and is fully committed to working together in the investigation.

Michael Canders, an Associate Professor of Aviation at Farmingdale State College, said this could be a case known as a "runway incursion" —- a critical safety failure where a vehicle or aircraft is on a runway when it shouldn't be. He noted that these tragedies often serve as the grim catalyst for industry-wide change.

"Sadly, we say that aviation regulations are written in blood," Canders said. "Meaning that there's a fatality and then maybe the regulations are changed. So it could be policies, it could be procedures, could be improvement on communications."

The FAA and NTSB investigation is expected to be extensive.

Investigators will conduct a "deep dive" into the communications and rest cycles of the controllers and drivers involved to determine the official probable cause.

"The bottom line is, we want to prevent it from happening again," Canders said.