The youngest member of the Kardashian clan, little North West, celebrated her second birthday in style over the weekend. Proud mum Kim Kardashian went all out for the big day, inviting a large group of family and close friends for an all-day bash at Disneyland in Los Angeles, but one family member missed out on the big day.

A large chunk of the Kardashian-Jenner family were in attendance, from eldest sister Kourtney and her children to Kendall, Kylie and even Kylie's boyfriend Tyga who brought along his toddler son.

However one glaring absence was North's doting auntie Khloé, who was nowhere to be seen on the day. Given that the sisters are so close-knit, many wondered why Khloé had chosen to give the party a miss.

Now though, it's been revealed that Khloé was "too upset" to attend the event, having just heard about the unexpected death of Jamie Sangouthai, who she knew closely through her estranged husband Lamar Odom.

"Khloé was too upset over Jamie dying. She wasn't there," a source told E! News this week.

Although Jamie is widely believed to have been a key factor in Lamar's drug addiction issues – which eventually led to the breakdown of his marriage to Khloé back in 2013 – he was still a valued friend of both, and his death by overdose on Sunday hit them hard.

Having cut Jamie off shortly before his death, Lamar is said to be "beating himself up" over what happened, so it's no surprise that Khloé felt equally at a loss. The reality star tweeted her devastation on Sunday night, writing, "when does it stop? RIP Jamie Sangouthai."

when does it stop? RIP Jamie Sangouthai

— Khloé (@khloekardashian) June 14, 2015

Khloé was one of the first to confirm Sunday's tragic news via Twitter, and has remained quiet on social media since.

Tributes were pouring in via social media last night after news emerged that Jamie Sangouthai, a close friend of Lamar Odom, had passed away.

Jamie reportedly died on Sunday in hospital after a heroin overdose. 

Although many believe the 37-year-old was a key player in the drug addiction issues that ended Lamar's marriage to Khloe Kardashian, the reality star herself took to Twitter last night to share her devastation at the shocking news.

"When does it stop? RIP Jamie Sangouthai," she wrote, followed by a series of broken heart and sad face emojis.

when does it stop? RIP Jamie Sangouthai

— Khloé (@khloekardashian) June 14, 2015

 

— Khloé (@khloekardashian) June 15, 2015

This morning she posted to Instagram to remind fans that life "doesn't get easier but I promise you that life will make you stronger."

Jamie will be known to viewers of Khloé and Lamar's ill-fated reality show, Khloé & Lamar, having appeared on both seasons as well as living next door to the couple during the show.

Khloé's longtime best friend Mailka Haqq also shared a touching tribute to Jamie via Instagram, posting a throwback picture of herself, Khloé, Lamar and Jamie in happier times:

 

Thru good and bad times life shows us every spirit matters and leaves a print on the hearts of others after they have passed… RIP Jamie Sangouthai #GodHelpUsAll

A photo posted by Malika (@forevermalika) on Jun 14, 2015 at 4:14pm PDT

Although Lamar himself has yet to make any public statement, sources close to the former NBA player say he has taken Jamie's death extremely hard.

"Lamar is beside himself. This is the worst tragedy," one insider told Us Weekly last night, with another source adding that the pair were "like brothers".

Our thoughts are with those close to Jamie at this hard time.