Friends, co-workers, and fans mourned the passing of Bill Paxton last weekend, after news broke that the actor had died on February 25. Having obtained his death certificate, People now confirms Paxton’s official cause of death was a stroke following surgery needed to “replace a heart valve and correct an aortic aneurysm.” Paxton underwent the procedure on February 14, later suffering complications that precipitated the stroke. The actor was 61.