GEOFF BENNETT: Let's shift our focus back to the Middle East and the tragedy at that hospital in Gaza.

Gaza's Health Ministry, controlled by Hamas, blamed Israel and said hundreds died in an airstrike.

That claim led to protests across the region and the cancellation of President Biden's scheduled summit in Amman, Jordan.

But the U.S. and Israeli Defense Forces say the cause was a misfired Palestinian rocket.

Nick Schifrin examines what we know.

NICK SCHIFRIN: It is one of the single deadliest incidents in Gaza since the war began.

At 6:59 p.m. Local time last night, an explosion hit Al Ahli Hospital in the yard where residents who considered the hospital a safe space had taken refuge.

Hamas blamed an Israeli airstrike.

But the Israeli Defense Forces released imagery it says shows damage caused by a Palestinian rocket that misfired.

The IDF also released a video with audio recording and translation of what Israel claims are to Hamas officials talking and purportedly admitting that the rocket had been fired from the cemetery next to the hospital and fell on the hospital.

U.S. officials tell me their preliminary assessment, using independent intelligence of imagery and intercepted phone calls, is that -- quote -- "Israel is not responsible."

For more on this, we turn to Marc Garlasco, the military adviser at PAX Protection of Civilians and a former Defense Department analyst with decades of experience in targeting and assessing bomb damage.

Marc Garlasco, thanks very much.

Welcome back to the "NewsHour."

Let's start with this photo that we're going to show right now.

You have visited countless, countless scenes of bomb aftermath.

What do you see in this photo?

MARC GARLASCO, PAX Protection of Civilians: Well, if you take a look at the physical evidence that we see here in the photo, I mean, one thing it says to me is, this was not an airstrike, right?

You don't have a three-to-nine-meter -- that's about a 10-to-30-foot -- crater that I would normally expect from an Israeli JDAM, which is a Joint Direct Attack Munition, a GPS-guided bomb, which is typical for what the Israelis would use here.

You also see a lot of surface damage and fire damage and very little damage to any of the buildings.

And these are some of the telltale signs that I would be looking for an airstrike, particularly from the types of weapons that Israel employs.

NICK SCHIFRIN: And you mentioned fire damage.

Let me show another photo, the aftermath of the strike, especially these burned cars.

Why is that significant?

MARC GARLASCO: Sure.

Well, when military weapons go off, they don't tend to have a long-term thermal effect.

You don't want to waste a lot of energy with fire.

And so they're trying to create a very rapid blast and fragmentation.

But as we saw in the video that you put up earlier, and as you can see here, there was a very high-temperature fire that lasted for quite a while.

That's not the kind of thing that we would see from the type of military munitions that Israel would use.

And, also, when you look at those cars, you don't see the fragmentation that you would find from a typical weapon that they would be using in an airstrike.

NICK SCHIFRIN: Hospital officials and Gaza health officials who are controlled by Hamas have said that the death toll is somewhere between 300 and 500.

Take a look at this damage, as you can see kind of a wider image of it.

Does that death toll sound possible to you?

MARC GARLASCO: Well, looking back at 20 years of the kind of work that I have done, that would definitely be at the high end of anything that I have ever experienced.

But we really need to focus on the civilians here, right?

There's a lot of he said/she said between the Israelis and the Palestinians.

We need to understand that the civilians are at the center here.

They're the ones bearing the brunt, whether it's Israeli civilians who've been murdered and are others that have now been taken hostage or Palestinians that are living under the bombs.

And we need to remember that they're not going to just be having the effects of the bombs when they strike, but there are going to be long-term reverberating effects affecting this population for many, many years.

NICK SCHIFRIN: And as we said, the Gazans who had collected in this yard in the hospital were only there because they had hoped that the hospital was a safe space, a place that they could go and be safe from Israeli bombs.

Let's talk about those Israeli bombs.

Israel has dropped more bombs on Gaza in the first week of this campaign, about 6,000 or so, than the U.S. dropped on Afghanistan in any single year of 20 years of war, as you know.

Israel says it only strikes Hamas targets, including senior officials, including rocket sites, which are often in residential neighborhoods, as well as Hamas weapons.

But what's your assessment overall of the Israeli air campaign so far?

MARC GARLASCO: Well, look, Nick, we're talking about a level of sustained firepower that is amazingly dangerous to not only civilian population, but also raises concerns of recklessness, right?

When you look at talking about potential war crimes, you have the issue of whether or not someone is actually targeting civilians.

I don't believe that the Israelis are purposefully targeting civilians here, but the questions are, are they being fast and loose with the law and are they really applying rules of engagement that are meant to protect civilians, or are they just going after Hamas with everything they have?

When we look at the U.S. air campaign in Afghanistan, that was over the size of a territory of about Texas, right, where you're looking at about 5,000 bombs annually being dropped there.

It got up to 7,000 in the last years of the Trump administration.

You're talking about 6,000 bombs in less than a week in Gaza, which is the size of Newark, New Jersey.

It's just incredibly dangerous to the population, and we need to have a cease-fire and get an end to this conflict as quickly as possible.

NICK SCHIFRIN: I have personally seen how Hamas will use neighborhoods in order to hide rockets, and also how Hamas officials will be targeted by the Israeli forces while surrounded by their family members, while surrounded by their extended family members often.

Israel, the United States calls that a kind of action using civilians as human shields, but it sounds like your concern is the Israeli rules of engagement when it comes to these airstrikes.

MARC GARLASCO: Well, look, Israel does have a right to defend itself, but that right is not unfettered.

They still have to follow international law.

They still have to follow distinction and proportionality, making sure that they're only targeting military objects, right?

I have been in Gaza.

I have been there after an air campaign.

I have been there after a ground campaign.

And I have seen what Hamas does and how they use the population.

But we still have to remember that you have a huge population within a tiny area that must be protected.

And I think the protection of civilians is one of the core issues that we need to make sure that Israel keeps at the top of its list of things.

NICK SCHIFRIN: But it sounds like, in terms of today, you're confident in saying that this does not appear to be an Israeli airstrike?

MARC GARLASCO: No, I don't think we have seen an Israeli airstrike here.

When you look at Israel's response to this and them saying that this was likely a Palestinian rocket that had been fired and failed, I think that that is certainly a plausible response, the idea being that, as that rocket was launching, it still had a substantial amount of fuel.

And when it tumbled from the sky, that crater that we saw, which is actually more like just a small hole in the ground, that was created by the kinetic energy of something hitting, and then there was an awful lot of accelerant, right, fuel mixed with explosives spreading throughout that hospital.

Unfortunately, you had Palestinian civilians jammed into that tiny area because they were trying to seek safety from this conflict.

And we have to ensure that this does not happen again.

NICK SCHIFRIN: Marc Garlasco, thank you very much.

MARC GARLASCO: Thank you, Nick.