Jack Callahan, center, and his five sons. Photo courtesy of Callahan & Sons

Family of the recently-deceased founder of John T. Callahan & Sons construction firm is asking that well-wishers contribute to the Massachusetts COVID-19 Relief Fund in his memory.

John “Jack” Callahan Jr. died March 29 from Alzheimer’s at the age of 90. A Randolph native, Callahan and his wife Marie founded the firm in 1954 and it grew into a trio of entities: Callahan Construction Managers, Global Property Development Corp. and JTC Development Corp.

“Our father taught us the keys to a successful business are strong relationships, excellence in service and community commitment,” Pat Callahan, his youngest son in president of the Bridgewater-based company, said in a statement. “My brothers and I look forward to continuing his legacy. Dad taught us that family extends beyond blood, and we have taken his approach into how we work with and treat our loyal staff across all of the Callahan Companies.”

All five of Callahan’s sons followed him into the family business. A Randolph native and three-sport athlete, Callahan played minor league baseball for the New York Giants and founded the North Randolph Little League. He was an enthusiastic supporter of his children and grandchildren’s own sporting endeavors, his family said, sometimes flying his private plane to their games.

Because of the inability to hold a public memorial, the Callahan family requested that donations go to the Massachusetts COVID-19 Relief Fund to benefit health care professionals and others affected by the health crisis.