An unusual number of suicides by top executives in Switzerland has prompted introspection in its business community over how senior managers are dealing with stress as its companies struggle to retain their status in the global economy. The death last week of the former chief executive of Zurich Insurance, Martin Senn, came less than three years after the insurer’s finance chief, Pierre Wauthier, took his own life. Wauthier had blamed pressure from the company’s then chairman Josef Ackermann in a suicide note, although Ackermann was cleared in a subsequent investigation. Acquaintances of Senn, 59, said he had been withdrawn since he was ousted from the company late last year, though few details of the circumstances that led to him shooting himself at his family home in the upmarket Alpine resort of Klosters have emerged. Martin Naville, chief executive of the Swiss-American Chamber of Commerce, said the business circles where Senn and Wauthier once moved had been left shocked, pondering what could have been done to prevent the tragedies.