Photo: Rodin Eckenroth/WireImage; George Pimentel/Getty

Khloe Kardashian and Tristan Thompson

Khloé Kardashianis recalling the harrowing moment she learned thatTristan Thompson’s mother, Andrea Thompson, had died.

In a preview for the season 3 finale ofThe Kardashiansnext week, the Kardashian-Jenner clan learns that the former NBA star’s momdied suddenly from a heart attack.

Kris, 67, explained to the cameras that “it’s been a rough week." Echoing her mother’s sentiment, Kim, 42, said, “This was just a really, really shocking way to start the new year.”

Crying, the momager imagined what it was like to be in Tristan’s shoes. “All of a sudden, you’re stripped of the caretaker that you had your whole life,” she told her two daughters.

In a confessional interview, Khloé, 39, shared that her ex was “screaming on the phone, trying to tell me that she’s gone.”

A source confirmed to PEOPLE that Andrea had died on Jan. 5 of a heart attack at her home in Toronto.TMZ Sportswas the first to report the news.

George Pimentel/Getty

Khloe Kardashian Opens Up About Harrowing Phone Call When Tristan Thompson’s Mom Died: ‘He Was Screaming’

Khloé, Kim and Kris thenattended Andrea’s funeralin Toronto on Jan. 14, another source confirmed to PEOPLE. A separate source also told PEOPLE that Kris spoke at the funeral services.

“They all want to be there for Tristan,” the first source said. “He will always be family. It’s a devastating situation for him. They want to do everything they can to support him.”

Tristan shares 5-year-old daughterTrueand a11-month-old sonTatum with Khloé. (He is also dad to 12-month-old son Theo withMaralee Nicholsand 6-year-old sonPrincewith exJordan Craig.)

Instagram/realtristan13

Khloe Kardashian Opens Up About Harrowing Phone Call When Tristan Thompson’s Mom Died: ‘He Was Screaming’

Exactly a month after his mother’s death, Tristan shared amoving poston Instagram, saying he was in the “deepest part of sorrow and grief.”

“Dearest mommy in heaven, it has been one month since you’ve been gone. I’m in disbelief,” he wrote in a lengthy caption alongside a series of snapshots of his mom, including one featuring his three brothers and Khloé.

The Good American founder also mourned the loss of Andrea in an emotional tribute on Instagram. “I have been avoiding this … Avoiding accepting this is real,” she wrote in the lengthy caption.

Jerritt Clark/Getty

Khloe Kardashian Opens Up About Harrowing Phone Call When Tristan Thompson’s Mom Died: ‘He Was Screaming’

Kris also posted an emotional tribute to Andrea on Instagram, sharing her “heartbroken” feelings over the “sudden passing.”

“You were themost amazing, dedicated, devoted, and selfless momand such a loving, kind, and fabulous grandmother,” she wrote. “What a blessing you were to your family!!! I will miss you Andrea. I will miss your bright spirit and amazing light.”

While the Kardashian-Jenner clan has had their ups and downs with Tristan — primarily due to theNBAplayer’s infidelity while he was dating Khloé — the family has shown up for him when he needed it most. Him and Khloé also remain on good terms as they successfully co-parent their children together.

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The season 3 finale ofThe Kardashiansairs next Thursday at 12 a.m. ET/9 p.m. PT on Hulu.

source: people.com