(CNN Philippines, March 24) — A "great pillar" of Philippine cardiology who was on the frontline of the country's battle against COVID-19 died on Tuesday, the Philippine Heart Association (PHA) said.

Dr. Raul Diaz Jara, an esteemed cardiologist and internist, also served as president of the Philippine Heart Association. Neither PHA nor Jara's family disclosed the cause of death.

PHA on Tuesday shared a letter from Jara's family on how devoted he was to helping his fellow Filipinos through his work.

"Papa is a tower of strength and leadership and he served as the head of our family and a beacon of hope for many in the midst of this crisis. He knew the extensive battle he was facing and he kept on fighting... As an internist and cardiologist, he is passionate about the art and science of his work. He took pride in serving the Filipino people," the Jara family wrote in a letter shared by PHA on Tuesday.

PHA also noted Jara's massive contribution and devotion to the advancement of Philippine cardiology.

"He was a great father, teacher, mentor, poet, author, singer, colleague, friend," PHA stated in a Facebook post. "One who has spent his life teaching. One who never got tired to impart knowledge and wisdom... Rest in peace, Dr Jara, as we remember you in our hearts and the teachings you have imparted to us. We deeply mourn for your loss but we want this more to be a celebration of your life. Philippine Cardiology will not be the same without you."

Several other frontliners have succumbed to COVID-19. Cardiologist Israel Bactol of the Philippine Heart Center, anesthesiologist Gregorio Macasaet III of Manila Doctors Hospital, and oncologist Rose Pulido of the San Juan de Dios Hospital have passed away recently, according to state news agency PNA.

Hospital staff are hit by the health crisis. In Medical City, 137 of their healthcare and frontline workers are in quarantine. More than 500 members of the staff of the UST Hospital are also under quarantine for possible coronavirus infection, The Varsitarian — the university's official student publication — reported.

The number of people who tested positive for the coronavirus disease in the Philippines jumped to 501, with the death toll remaining at 33. The number of patients who have recovered is now at 19.