Bill Holmes, a transplanted Midwesterner who amassed a fortune selling pools and spas in Southern California, has made a $27-million gift to CHOC Children Hospital, reports the Orange County Register.

The donation is the largest by a living donor to the Orange, Calif., institution, and pushes it past a $125-million fundraising target well ahead of campaign’s June 30 close.

Mr. Holmes’s name will adorn a seven-story tower set to open on the hospital campus in the spring that will house a pediatric emergency department and other facilities. The gift, announced at the hospital’s annual gala Thursday, marked a philanthropic coming-out of sorts for the retired entrepreneur, who had previously maintained a low profile while supporting local and national charities.