 Actually firing the cannon was the most dangerous job, but the swabber had to endure brutal heat. The just-fired cannon would be incredibly hot. William Hayes was a swabber. He was overcome by heat during the Battle of Monmouth. His wife fetched buckets of water to cool him down and then took over when her husband collapsed. That's how Mary Hayes became known as Molly Pitcher on this day, June 28, 1778.