Bruna Valeanu, a 24-year-old student from Brazil, had recently moved to Israel. She was attending the Supernova music festival in the southern part of the country when Hamas militants attacked and killed hundreds of people – including Valeanu, "CBS Evening News" anchor Norah O'Donnell reports.

Her family is new to the country. They were planning a funeral for Tuesday but don't know many people. To hold a Jewish religious service, a quorum of at least 10 people need to attend, called a minyan. The family didn't know if they could hold a prayer service for her funeral.

They posted on social media asking if 10 people could attend, O'Donnell reported on "CBS Mornings" on Wednesday.

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But they got much more than that. Tens of thousands of people showed up to pay their respects for Valeanu, O'Donnell reports. 

One person who attended the minyan told the Jerusalem Post there was traffic heading to the cemetery. "My friend and I went after they wrote that there would be no minyan," said Orit, who was only identified by her first name. "During the trip, Waze added more and more travel time even though the road was open, and we didn't understand why. Towards the cemetery, there was a very big traffic jam and we thought there might be a lot of funerals, we didn't realize that they were all coming for Bruna."

At least 260 people died at the music festival, but officials said that number was expected to increase, the Associated Press reported Sunday. Witnesses said rocket fire, followed by gunshots, came out of nowhere, according to Israel's Channel 12.

Valeanu's sister, Nathalia Valeanu, told the Jerusalem Post that her sister became separated from her friends at the festival. "The last thing we got was her location via text. It was a dangerous location, where terrorists came armed in trucks, tanks, and motorcycles," she said. "She said she heard a lot of gunshots and had a lot of people injured. And she was in the middle of the woods, but it was a place that was kind of fenced in."

Some people at the festival were taken hostage by Hamas, including a student named Noa Argamani. Images of Argamani's capture were shared on social media, and her father, Yaakov Argamani, told CBS News: "She is an amazing person. A sweet child."

The parents of an aspiring DJ who went missing at the festival told CBS News they have been in contact with authorities, but do not know where their son is and hadn't heard from him since Saturday.

"We need everyone who can do something to bring us back our boy. That's what we need. We need someone to bring us back our boy," Laor Abramov's mother, Michal Halev, told CBS News' Jericka Duncan.

Since Hamas launched its attack on Israel on Saturday, thousands of people have been killed in the country, officials said. Thousands have also been killed in Gaza as Israel launches airstrikes on the area. 

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Caitlin O'Kane

Caitlin O'Kane is a digital content producer covering trending stories for CBS News and its good news brand, The Uplift.