Jordan Feldstein, the longtime manager of rock band Maroon 5, died from a heart attack Saturday night (Dec. 22). He was 40.

Feldstein, also the brother of actor Jonah Hill, successfully managed Maroon 5 from the group’s start more than 15 years ago. As the CEO/founder of Career Artist Management (CAM), he also helped guide the careers of artists like Miguel, Robin Thicke, Elle King, Big Boi, and others. CAM is based in Live Nation's Beverly Hills headquarters.

Feldstein, who was childhood friends with Adam Levine, also played an instrumental role in negotiating Maroon 5 frontman's coach role on NBC’s The Voice.

In 2015, CAM teamed up with London-based Tap Management, adding Lana Del Rey managers Ben Mawson and Ed Millett to its executive team. Feldstein was named No. 96 on Billboard's Power 100 list last year.

"All relationships are ­reciprocal," Feldstein said at the time.

Feldstein’s family released the following statement following his death:

Unfortunately, last night Jordan called 911 for shortness of breath, when paramedics arrived it was determined he went into full cardiac arrest and passed away shortly thereafter.

His family asks for privacy during this difficult and unexpected time.

In lieu of food and flowers, the family will announce a charity in the coming weeks where memorial donations can be made in Jordan’s name.