After the late 1340's onset of the Plague, Italy suffered a devastating loss of population, especially in urban areas. The city of Pisa provided sea port and a valuable trade route, but also exposed Italy to the the Plague carried by merchants and soldiers passing through. With many cities losing as much as 60% of its population, death was a subject of contemplation and discussion. Artists of the time had plenty of gruesome scenarios to show the world, and an all too understanding audience.
To many, it was God's punishment. The Triumph of Death, a massive fresco displayed on the wall of the Camposanto, tells of the inevetability of death and compels sinners to repent. Like most religious art of the time, it criticized those who revel in luxury and the corporial world. With things like money seeming less important, an art commision for a holy cause became a popular thing. Aside from religious interpretation, the Plague left behind many artists who felt a need to memorialize the dead and the living in many ways.
All in all, the Plague damaged the population of Europe and Italy but in a strange way, fueled art production by providing artists with a common subject and the money of the guilty to pay for it.