An insider tells PEOPLE that Jenner is "very upset" and supporting Guerrero's family "financially" Kylie Jenner is mourning the loss of a close friend. A source tells PEOPLE the mogul is "shocked" by the sudden death of her longtime hairstylist Jesus Guerrero.

Stars paid tribute to the hairstylist after he died "very suddenly and unexpectedly," according to his family.

Jesus Guerrero, a celebrated hairstylist, died suddenly over the weekend. He was 34. Guerrero was abroad for a job when he began feeling unwell. He returned to the U.S., where he passed away in the hospital due to complications from pneumonia, according to social media posts.