June 6, 2023 Russia-Ukraine news

Ukrainian troops witnessed Russian soldiers being swept up in flood waters and fleeing the east bank of the Dnipro River after the collapse of the Nova Khakovka dam, an officer in Ukraine's armed forces said. Many Russian troops were killed or wounded in the chaos, according to the officer. 

Capt. Andrei Pidlisnyi said when the dam collapsed in the early hours of Tuesday morning “no one on the Russian side was able to get away. All the regiments the Russians had on that side were flooded.” 

Pidlisnyi told CNN he believed the Russians had deliberately attacked the dam to disrupt Ukrainian forces’ plans for an upcoming offensive. 

Pidlisnyi explained that the lie of the land around the river meant that Russia’s military — located on the east bank — suffered serious impacts in the dam’s breach. His unit was able to watch the events unfold through the use of drones and troops on the scene.

The Russian units in harm’s way may not have been warned, possibly to maintain the element of surprise, Pidlisnyi said.

Pointing blame: Ukraine’s government has echoed Pidlisnyi’s contention that Russia deliberately blew up the dam, while the Kremlin has said it was Kyiv’s forces that carried out an attack. 

In fact, evidence to conclusively support either side’s claim is yet to emerge, while analysis of videos of the dam, and its subsequent breach, and in particular examination of satellite imagery, suggest the collapse could have been the result of structural failure since the Russians occupied the dam in March last year.

Watch:

Ukrainian President Volodymyr Zelensky again blamed Moscow for the collapse of the Nova Kakhovka dam and said Russia should bear “criminal liability” for “ecocide."

"In our opinion, this is a crime, the Prosecutor General's Office has already registered it. It will have evidence. There is a modern classification — ecocide,” Zelensky said in an interview with national media on Tuesday.

Adding, "I think that there should be criminal liability... International institutions, including the International Criminal Court, should react."

Both Kyiv and Moscow accuse each other of being behind the major breach of the dam, although it is not clear whether the dam was deliberately attacked or whether the collapse was the result of structural failure. 

Zelensky referred to a report by Ukrainian intelligence last year that claimed occupying Russian troops had mined the dam. 

Between 35 and 80 settlements were expected to be flooded due to the breach, he said, and his government was working to provide residents in flooded areas, and those neighboring it, with drinking water. 

In a tweet later on Tuesday, Zelensky said he had spoken to the head of the International Atomic Energy Agency, Rafael Grossi, and that they had “discussed ways to minimize risks to #ZNPP [Zaporizhzhia nuclear power plant] security,” which Grossi is due to visit next week. 

The ZNPP uses water from the dam at Nova Kakhovka to cool its nuclear reactors.

Residents downstream from the Nova Kakhovka dam on the Dnipro River in Kherson were told to “do everything you can to save your life,” according to the head of Ukraine’s Kherson region military administration, as video showed a deluge of water gushing from a huge breach in the dam.

The critical dam is the largest reservoir in Ukraine in terms of volume. It’s the last of the cascade of six Soviet-era dams on the Dnipro River, a major waterway running through southeastern Ukraine. There are multiple towns and cities downstream, including Kherson, a city of some 300,000 people before Moscow’s invasion of its neighbor.

Here are some images showing the dam's damage and flooding in the area:

CNN's Cody McCloy contributed to this post.

Problems due to the collapse of the Nova Kakhovka dam can be avoided at the Zaporizhzhia power plant if "necessary measures are taken," Ukraine's state nuclear regulatory inspectorate said.

The plant uses water from the dam, which collapsed Tuesday prompting evacuations in the area, to cool its nuclear reactors. It is the largest nuclear power station in Europe.

Ukraine’s state-owned nuclear power company Energoatom had considered the “possible impact of a decrease in the water level in the Kakhovka reservoir” prior to the dam’s collapse and had ”developed measures for such a case,” the inspectorate’s statement read. 

The International Atomic Energy Agency said on Tuesday that the plant’s reactors had been shut down “for many months," according to a statement. The ZNPP has been occupied by Russian troops since Moscow’s full-scale invasion of Ukraine in February last year. 

The collapse of a major dam and hydro-electric power plant in Russian-occupied southern Ukraine sparked mass evacuations and fears for large-scale devastation as Kyiv accused Moscow’s forces of committing an act of “ecocide.”

In recent days, Ukraine’s forces have increasingly taken the fight to Russia’s entrenched front lines in the south and east ahead of a widely expected summer counter-offensive.

Mykhailo Podolyak, who is a senior aide to Zelensky, said the dam’s collapse would “create obstacles for the offensive actions of the Ukrainian Armed Forces.”

Here are the latest headlines related to the dam's breach and other news from the war:

CNN's Jonny Hallam, Josh Pennington, Helen Regan, Olga Voitovych, Irene Nasser, Sebastian Shukla, Ivana Kottasová, Gianluca Mezzofiore and Jo Shelley contributed reporting to this post.

The collapse of the Nova Kakhovka Dam could flood "at least 37 villages and settlements" according to estimates from Ihor Syrota, the CEO of Ukrhydroenergo, which oversees all the hydropower plants in Ukraine — including the plant at Kakhovka before the Russians occupied it last year.

People who live on the Russian-occupied east bank of the Dnipro River face the “biggest threat” because they are located on lower ground, he said. 

Ukraine's Energy Minister Herman Halushchenko said he believes there could be up to 80 settlements affected in both Ukrainian-held and Russian-occupied territory.

“The west bank is higher, so there will be less flooding there,” Syrota said. 

However, even in Kherson city, on the west bank, “the water level will rise more than three meters,” Syrota said. 

Syrota said he thought water levels would peak on Wednesday morning at around 5 a.m. local time. 

Syrota outlined some of the dangers of the dam breach. 

“The environmental consequences will, of course, be significant. First of all, the Kakhovka reservoir is likely to be drained to zero, and we understand that the number of fish will gradually go down," he said.

Syrota repeated the Ukrainian government’s version of events, which is that the Russian troops occupying the plant had “blown up the plant.” 

He said this “will have damaged the equipment at the plant,” causing oil to spill into the water. 

Both sides accused each other of being behind the major breach of the dam, although it is not clear whether the dam was deliberately attacked or whether the collapse was the result of structural failure. 

“Four hundred tons of turbine oil is always there, in the units and in the block transformers that are usually installed on this equipment,” and some of the oil spilled out, he claimed. “It all depends on the level of destruction of the units and this equipment… If the damage is extensive, then all the oil will leak out.” 

Syrota said that the Kakhovka reservoir could not be blocked until the east bank was freed from Russian occupation, “because it needs to be blocked from the east bank to the west bank.” 

CNN correspondent Fred Pleitgen reported from the southern Ukrainian city of Kherson, where several areas of the city have flooded following the collapse of the Nova Kakhovka dam. 

More than 1,000 people have been evacuated from Kherson and other Ukrainian-held parts of the region following the collapse, according to local officials.

"(In) the very short time that we've been on the ground here, we could see this water already rise considerably," Pleitgen reported.

Watch CNN's reporting:

The European Union is mobilizing support to help Ukraine following the collapse of the Nova Kakhovka dam, EU Commission President Ursula von der Leyen said Tuesday, describing the collapse as it as “outrageous attack” from Russia.

It is unclear what caused the dam to collapse, which came as Ukraine geared up for a widely anticipated counter-offensive. Both Ukrainian and Russian officials said the dam collapsed in an explosion and are blaming each other for it.

Russia has “strongly” rejected all responsibility for the incident with Kremlin spokesperson Dmitry Peskov saying Moscow “unequivocally” believes it to be “deliberate sabotage” by Ukraine. 

The EU is mobilizing support through its civil protection mechanism, von der Leyen said, adding that the bloc is working hard to ensure the rapid delivery of dirt water pumps, fire hoses, boats and mobile water purification stations. 

The leaders of member states, including those from Germany and Ireland, came out condemning the incident.

The bloc’s chief diplomat Josep Borrell didn’t hold back either, saying in a statement that the “attacks” represent a “new dimension of Russian atrocities.”   

The White House is closely monitoring the impacts of the collapse of a major critical dam on the Dnipro River in Ukraine.

White House National Security Council Coordinator for Strategic Communications John Kirby said the United States is looking into reports of what could have possibly caused the collapse, but made clear that "we cannot say conclusively what happened at this point.”

Kirby wouldn't say if the US has concluded that Russia is likely behind the collapse, or if it was even an intentional act.

Some context: The critical Nova Kakhovka dam is the largest reservoir in Ukraine in terms of volume and is the last of the cascade of six Soviet-era dams on the Dnipro River — a major waterway running through southeastern Ukraine. There are multiple towns and cities downstream, including Kherson, a city of some 300,000 people before Moscow invaded its neighbor. 

The dam's collapse, which powers Ukraine’s Kakhovka hydro-electric power plant, could “very well have a devastating impact on Ukraine's energy security, and it will certainly have an impact on Ukraine's canal system,” Kirby said, prompting the US to reach out to Ukraine to provide humanitarian assistance. 

Still, Kirby declined to say what, if any, effect the United States thinks the dam collapse will have on Ukraine’s summer counter-offensive.