We want to talk about the breaking news at a New York border crossing. The FBI is investigating a vehicle explosion there. This is at the Rainbow Bridge, u s. Canada border crossing. Let's get straight to CNN's Bryn Gingrass with the latest details. Bryn, bring us up to speed.

Yeah, Boris, the FBI, the ATF the JTTF, which is the Joint Terrorism Task Force, there's a number of federal authorities both on the US. Side and also on the Canada side that is monitoring the situation, trying to figure out exactly at this point what happened. What we know is that there was a car crossing into the US. From Canada, and what has been described as some authorities as a crossing there at the Rainbow Bridge and then a subsequent somewhat explosion is what the FBI is describing. Now, whether or not this was sinister or not is not clear at this point. However, as you can imagine, at this point of entry, it's going to be an uptick in security across that area. So that is what we are seeing currently. In response, as this is still being investigated, we're hearing there is a system wide security uptick at this point due to this explosion. That means there are going to be more security checks of cars in that area, around the airports in that area, and more security screenings of passengers who are coming in and out of this area. Now, of course, with the holiday, that was already sort of being an uptick, certainly as we've seen more travelers during this time.

But this has sort of definitely raised it to another level. So, again, it's very unclear at this point what exactly happened at that crossing. We're still trying to get those answers as authorities are also on the ground there investigating. But again, there is an uptick in security. And we also know from the JTTF that all points of entry into the state of New York are being closely monitored at this point. So still trying to get some answers, Boris, but that's the very latest that we're hearing on the ground there.

Brynn, please stand by. I just want to let our viewers know, these are live images of the scene that we are watching. It appears that law enforcement is there in large numbers, diverting traffic away from the crossing area. I want to go to CNN's John Miller, because John, you have some new reporting. You've spoken to multiple law enforcement sources. You have details about some of what unfolded. What are you hearing?

Well, Boris, right now what they're looking at is trying to get to all the video so that they can kind of re piece together what happened. So all of this is still preliminary, but what we're being told is this car was coming into a checkpoint, went through the first checkpoint where they examined driver's license, passport, and so on, and then was referred towards a secondary checkpoint. Now, from people who have looked at the videos. They say the car reaches a high rate of speed, apparently crashes into some kind of barrier, and there's an explosion. So that's what we know from what they think they have pieced together at the scene. Here's what we don't know. And these are all important questions, which is what was it that made the car increase speed and strike the barrier? Did the explosion happen because there was something inside the car that blew up or because it impacted something hard, flipped over and exploded as a result of the accident? I use the word accident. What I mean is collision. Who are the two individuals who were in the car who were seriously injured? We don't have their condition yet, but it is supposed to be, according to my sources, what they believe to be two males.

And as soon as they have those identities, they will be going backwards through their records, their intelligence. Who are these individuals? Where were they going? Where were they coming from? In the meantime, that's a crime scene where the FBI's, bomb technicians, ATF's, bomb technicians, the county sheriff's, bomb technicians from the Buffalo side will all be looking to determine what may have been in that car, whether it was the car that exploded or whether it was something inside the car that exploded. So these are all very serious questions.

Yeah, it's literally unfolding before our eyes. John, just to clarify a point you made, it appears from the reporting that this car went through the initial security screening and then there was a second search, or there was an attempt at a second search, and it was at that point that the car then sped and collided.

Well, at that point, the car increases speed. And right after that, there's an explosion. And this is where, depending on which witnesses you're talking to or who viewed which videos, the story becomes divergent because what is not clear is did the car explode because of or upon some impact? Or did the car explode because there was something in the car that blew up and then caused the impact? And that's what they're trying to look at every angle of the video, talk to every witness, but also forensically identify what's in that car. At the same time, they're dealing with a separate suspicious package that's been found at the scene, which they'll work their way through, which may or may not have anything to do with this. That's common in these situations. But really the best piece of evidence, physical evidence, that may contain those answers is going to be that vehicle. And that means chemical tests. It means going through the wreckage. It means looking for signs of something that blew up to determine was that a spontaneous combustion upon impact, fueled by the gas tank and fuel and other things, or was there an improvised explosive device?

These are questions right now, not answers.

Right? I do want to note we've just gotten word that Canadian officials are going to be holding some kind of press briefing to provide us with potentially some of those answers to the questions that John brought up. I want to bring in former Boston Police Commissioner Ed Davis, who joins us now. Thank you so much for joining us, Ed. I wanted to ask you something about what John brought up. The fact that this car was apparently selected for secondary screening, what is it that would prompt some official to see something in a car, to say that that vehicle needs to be screened further? Because it sticks out to me that between getting from that first checkpoint to the second one, the car sped up and then there was an explosion.

Good afternoon, Boris. Yes, this is a clue, I think, as to what may be going on here. It's hard to say at this juncture, and John is correct in saying it's very early in the investigation, but all of the agents on the borders are trained in something called suspicious indicators. And so anything that might have happened either in the exchange with the driver of the vehicle or his passenger or something that they saw inside the vehicle that caused them concern, they do have explosive stiffing dogs there. Again, that's just speculation, but there are a multitude of things that could have happened that raised the suspicion of the Border Patrol agents, and that's exactly why they're there. They're doing their job. And if they started to expand their search and the two suspects knew that they were going to get caught, anything's possible.

I do want to pause for a moment because it appears the Canadian officials are set to brief at any moment, but it has not yet started. So we will bring it to you as soon as it does begin. Okay, Ed, please stand by. I believe we also have Josh Campbell. CNN's Josh Campbell with us. Josh, you've just heard the latest details about what is unfolding at the Rainbow Bridge, US canada Crossing. What stands out to you about this reporting?

Well, as you've mentioned before, it's too early right now to tell whether we're talking about terrorism, whether this was an accident. I mean, there's so many possibilities here. But what is clear is that the FBI, every field office, 56 offices across the country, has a Joint Terrorism Task Force. And what those agencies do. It's not just Bureau of Personnel, but a host of other agencies. Customs and Border Protection, local police, state police. All the resources and databases that you would bring to bear to try to determine who are these individuals? Do they have any type of criminal history that would help you then piece together a possible motivation here? Obviously conducting interviews with these people as well. But within the FBI, there's a specialty that's called an SABT. That stands for Special Agent Bomb Technician. They would launch to the scene, and I think we would be able to quickly rule out whether there was some type of incendiary device because they would do their testing, their chemical testing, take samples from in and around the area to see if any of those samples actually match with some type of explosive. So that happening behind the scenes.

That wouldn't take long in order to make that determination. So you have multiple moving parts. I will say, though, as far as the border checkpoint, among the tens of thousands of law enforcement agencies throughout this country, there exists exactly one that has the greatest power when it comes to stopping people, and that's US. Customs and Border Protection. These officers can stop someone for any reason or for no reason at all in order to conduct secondary screenings. Oftentimes they'll do random selections of people at the border as well. And so it's too soon to determine why this particular vehicle was then called over to secondary inspection. But it's worth pointing out that that is the power and authority that they have. But that would obviously be a key question as well for authorities. Was there some type of indicator that the border checkpoint officers something that raised their suspicion? And then we'll just have to wait and see what the chemical analysis does. Obviously, the interviews, the looking into the background of these people, the last thing I'll say as well is that anytime that there's some type of potential terrorism, which again, we're not saying that this is that far too soon to say that, but you start looking at, well, what are possible targets of terrorism?

And you don't think a booth at a border checkpoint would be among those if someone was trying to get in the country in order to do something incendiary. There are multiple other potential targets as well. Obviously, we don't know exactly what happened at the border, but again, the bottom line, there's a lot of work going on behind the scenes right now, far too soon right now to tell whether this was something center, Senator, whether this was accidental. Bores.