Fortress Investment Group announced the unexpected death of Josh Pack, its co-CEO and managing partner. He was 51.

Fortress has $51B in assets under management, with investments in real estate, corporate credit, private equity and asset-based finance. Pack joined the Fortress Credit Funds business at its inception in 2002, according to his LinkedIn profile.

“We are devastated by this loss,” Fortress said Monday in a statement on its website. “Josh was a gifted investor, a thoughtful strategist, a compassionate leader — and a deeply cherished friend to many.”

Pack oversaw Fortess’ investments in private credit, private equity, real estate, real estate debt, net lease, distressed and opportunistic investing throughout his 23 years with the company. Before that, he was a vice president with Wells Fargo & Co.

The alternative asset management firm has headquarters in New York City and Dallas, where Pack was based. Pack told Bloomberg in an interview published in May that he planned to move to London as part of a push for Fortress to expand in Europe.

At the time, Pack said Fortress was reinforcing its investment strategies and growing them “probably faster than we had initially planned.”

Along with Europe, Fortress was focused on growth in the Middle East and Asia, with the latter particularly related to private wealth, Bloomberg reported.

Its recent commercial real estate deals include the acquisition of a 1M SF UPS portfolio, including its headquarters outside of Atlanta, for $368M in September. It is also implementing an $8M renovation at the Design Center of the Americas showroom in South Florida after enacting one of the largest UCC foreclosures in history last year to take control of the 780K SF office property.

Founded in 1998, Fortress has offices in eight countries, including Italy, England, Spain and the United Arab Emirates. It is backed by Abu Dhabi sovereign wealth fund Mubadala Investment Co., which bought a stake from Japan’s SoftBank Group Corp. in 2023, Bloomberg reported.

Co-CEO and Managing Partner Drew McKnight will continue to lead the firm, and Jack Neumark will step into the co-CEO role alongside him, the company announced. Nuemark has been a managing partner of Fortress since 2023 and became president in January, according to his LinkedIn profile.

“Josh left an indelible mark on our institution. He cared deeply for his team, and that care was returned in kind,” Fortress said in its statement.

“Most importantly, Josh was a devoted husband and father. We extend our heartfelt condolences to his family and ask that their privacy be respected during this tragic time.”