On this day, April 15, in 1948, President Manuel Roxas gave a speech at the Clark Air Base. Moments later, he had a heart attack that killed him. Elpidio Quirino replaced him and finished the remainder of his term.
The official calendar of the Republic of the Philippines: an almanac of Philippine commemorations enlivened with illustrations and information. –Manila: Presidential Communications Development and Strategic Planning Office, [2014].
On this day in 1912, the Titanic sank on its maiden voyage to New York from Southampton, Hampshire, England.
https://www.britannica.com/on-this-day/April-15
On this day in 1941, Igor Sikorsky made his first flight with his invented helicopter. His flight lasted 65 minutes.
https://todayinsci.com/4/4_15.htm
This month of April is National Hemophilia Awareness Month (Proclamation No. 1478, s. 2008)