"It's just a fabulous organization that we're pleased to be a little part of," Richard Lundquist said.
Their contribution will go toward the hospital's orthopedic and spine institute as well as a neuroscience institute.
"It's really important that people across this country recognize, you know, if you live in the wrong zip code, you might be a DOA," Melanie Lundquist said.
The donation brings the couple's contributions to the hospital over the years to a historic $100 million.
"Community hospitals really, really need to be able to provide extraordinary service," said Melanie Lundquist.
The couple was honored by dozens of people at a breakfast on Thursday, including hospital personnel and local leaders praising the generous gift.
"We trust the doctors. We trust Torrance Memorial, and this continued generosity from Melanie and Richard supports the good work that's happening here and will certainly save lives," said Los Angeles County Supervisor Janice Hahn.
The Lundquists were also presented with their own physician white coats, complete with the logos of the institutes their most recent donation will benefit.
"We're very, very appreciative for the opportunity to do this for the community," Melanie Lundquist said.
A statement released before the Thursday event stated that the $100 million represents the largest contribution from one donor to a non-teaching/non-research hospital in the nation.