As an Israeli volunteer who recovers corpses, Moti Bukjin has worked at horrific disaster sites for decades, but nothing readied him for the carnage Hamas gunmen unleashed on a desert music festival on Saturday.
"It turns out things can be much, much worse," he said.
He was among the first responders to the site of the massacre at the Supernova festival at a kibbutz near Gaza, where 270 revellers were gunned down or burnt in their cars.
Most of them were young people in their party dress who had danced through the night under the stars.
Soon after the sun rose above the Negev desert on the Jewish Sabbath, survivors recount, rockets started streaking through the sky from nearby Gaza.
The revellers were stunned by what they saw next: Islamist militants with assault rifles racing toward them in trucks, on motorcycles and even flying motorised paragliders.
Spraying gunfire, they "butchered people in cold blood, in an inconceivable way", Bukjin said, detailing that many victims had been shot in the head at close range.
Describing the aftermath, he said, "they were shot trying to flee and fell into the ditches on the side of the road".
It was obvious the militants had time to act methodically, Bukjin told AFP.
"They had so much time till the security forces got there. Some of the cars, they burnt with people inside. We saw a gunshot to the head, a bullet to the head, a bullet to the chin."
It showed the killers were "not randomly spraying bullets and hoping they hit", he said.
The scale of Saturday's massive and multi-pronged surprise attack from Gaza has shocked Israel and amounts to the deadliest assault in the country's 75-year history.
Under the cover of a barrage of thousands of rockets, the Hamas militants also swarmed into nearby Israeli towns and kibbutzim, gunning down civilians.
Hamas took at least 100 hostages -- including several from the festival -- and abducted them back into Gaza, where some were paraded before cheering crowds.
One mother, Ahuva Mayzel, last heard from her 21-year-old daughter Adi, who was at the festival, an hour after sunrise.
"It was our last call, in which we heard a lot of noise and shootings and bombing -- chaos, total chaos," she told journalists from her home in Karnei Shomron, an Israeli settlement in the occupied West Bank.
Waiting for news of her daughter, Mayzel said "we are just helpless, completely helpless as her parents.
"Really, this is unimaginable. So many casualties, so many dead, so many missing."
Aerial footage of the scorched festival site showed the main tent still standing and dozens of cars piled up, many charred, in a sign of the panicked rush to speed away.
"There were cars on the side of the road, an overturned car, a car on its side -- in each car there were two or three bodies, or just one body shot dead," Bukjin said.
His religious charity Zaka recovers bodies in accordance with Jewish law and was moving on to other sites in southern Israel.
"It's going to be a rough day," he said gravely.
One of the survivors of the festival attack, Ephraim Mordechayev, 23, said he was having "the happiest moment of my life" when the joy turned to horror.
He had just partied through till sunrise "with people I love, (in) a place I love" when he noticed Israel's aerial defence system intercepting rockets, he said.
At first, "we didn't comprehend the scope of the event", he told AFP, back in his apartment in the northern city of Or Akiva, still wearing the festival wristband.
Many party-goers were packing up their cars and heading for the exit when he heard the first bursts of gunfire.
"I looked back and saw that in the car behind me there were three corpses, and all the cars' windows were shattered."
As he spotted militants firing from motorised gliders, Mordechayev got out of his car and ran for his life.
He hid in bushes for a terrifying wait, until a packed passing car stopped and picked him up before racing off to the safety of a military base.
Mordechayev, who has served more than five years in the army, was stunned at how such a joyful event could turn into the worst nightmare of his life.
"Nobody was armed," he said. "They came to enjoy the party."
