The Leona M. and Harry B. Helmsley Charitable Trust announced a $29 million grant today to help repair the Weizmann Institute of Science’s Rehovot campus, the largest donation in the year since a devastating Iranian missile attack caused approximately $635 million in damage.

In the midst of Israel’s 12-day war with Iran last June, two missiles struck the institute, one of the world’s preeminent research institutions in the natural and exact sciences. The barrage not only destroyed or damaged a total of 52 research labs, 100 buildings, 5,600 pieces of equipment and 25,500 bacterial and DNA samples — it also cost hundreds of scientists years of work. 

Scientists scrambled to recover what they could and move to temporary facilities, but the damage was done — to cancer research, immunotherapy development and the institute’s ability to collaborate with many of its partners — and last year, the institute plummeted out of the top 100 in global research rankings in the 2025 Nature Index, a listing of top research institutions.

The grant from the Helmsley Charitable Trust is one of the largest contributions to rebuild the institution, alongside The Jack, Joseph, and Morton Mandel Foundation, which donated $26 million in September. The process will take years, and the grant will go towards rebuilding floors three through seven of the Wolfson Building for Biological Research, which is projected to reopen in 2027 with 17 labs and a new immunology research wing. 

“We are committed to helping to preserve and strengthen this unique center of discovery and learning and helping their scientists, students, and staff return to their research. Mankind cannot afford to lose the Weizmann Institute,” Sandor Frankel, a trustee of the Helmsley Charitable Trust, said in a statement.

Founded in 1999, the Helmsley Charitable Trust focuses on six program areas: strengthening the health, safety, and security of people in Israel; improving healthcare access in rural America; research and support for patients with Crohn’s disease; research and support for patients with Type 1 diabetes; supporting vulnerable children in Sub-Saharan Africa by helping rural communities build resilience; and improving healthcare delivery and access for high-needs patients in New York City. Since 2010, the trust has provided over $780 million in grants to Israel, including $80.7 million to the Weizmann Institute, and supported Israeli medical institutions, including Hillel Yaffe Medical Center, Hadassah-Helmsley Medical Center and Soroka Medical Center (the last of which was also devastated by an Iranian missile during the 12-day war last year).

“One of the Weizmann Institute’s greatest strengths is the generosity and passion of its supporters,” Alon Chen, the institution’s president, said in the statement. “The Helmsley Charitable Trust has been a committed and generous partner to the Institute. This grant comes in response to an unprecedented attack and is instrumental in accelerating our rebuild while helping scientists resume their world-changing work.”