America's most dangerous jobs

• Fatality rate per 100,000 workers: 40.5
• Median wage: $34,220

Roofers face an inescapable hazard of the job, height, that amplifies the chances of suffering critical injuries in accidents. A slip 40 feet up is inherently more dangerous than one on the ground.

But falls are just one of many dangers they face, according to the Union of Roofers, Waterproofers and Allied Workers. There are also burns, electrocutions, chemical exposures and hoisting accidents.

Better safety training and stricter guidelines on the use of guardrails, harnesses and other systems have sharply cut fatality rates. Particularly helpful are warning lines: These ropes are strung a few feet from roof edges so workers can feel when they're near the point of accidentally stepping off.

NEXT: Ironworkers