TV personality Khloe Kardashian has reacted after learning about the death of Jamie Sangouthai -- the best friend of her estranged husband, former NBA basketball player Lamar Odom. Sangouthai was a fixture on the couple's short-lived reality show, “Khloe and Lamar."  His death Sunday was apparently caused by a heroin overdose.

The reality star took to Twitter and Instagram to express her grief shortly after finding out about the grim news. She had just been gushing about her trip to Hawaii when the news broke. Kardashian’s joyous mood quickly plummeted to the ground in the span of a few hours.

Kardashian’s best friend Malika Haqq, who is also in Hawaii, posted a small tribute to Sangouthai on her own Instagram account. She posted a throwback photo showing Kardashian and Odom during happier times along with their respective best friends, herself and Sangouthai. She wrote: “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"

According to a report by showbiz website TMZ, the 37-year-old died of an apparent heroin overdose. He was taken to a hospital in downtown Los Angeles on Sunday after a 911 call. No official statement has been issued.

Sangouthai’s problems with substance abuse have never been a secret and it was even highlighted in several episodes of “Khloe and Lamar.” The TMZ report shared a clip from the show where he is seen half-awake on a couch in an apartment that Odom pays for. The place is strewn with bottles of liquor, cigarettes and various other pieces of trash.

Odom forces him to shower after commenting that he stinks. He is then left to sober up and recover in bed. In that episode, Kardashian had been forcing Odom to put his affairs in order. This included cutting off his friends who live off him. Odom had been supporting Sangouthai and had appointed him to manage his website and online merchandise store. Upon inspection, Kardashian found out that the merchandise hadn’t been restocked and the business was poorly functioning.

When Kardashian filed for divorce from Odom in 2013, citing infidelity, Sangouthai was among the people who pushed Odom into his now infamous crack binge. Odom ran into trouble with law enforcement due to his drug use.

Sangouthai and Kardashian have never had a smooth relationship but she made a point of reaching out to Odom’s friends and family. He is one of Odom’s closest friends from high school and they have been inseparable ever since. Despite butting heads with Sangouthai in the past, Kardashian is clearly devastated by the loss.