JACKSONVILLE, Fla. — Skylights are a useful way to allow sunlight into a room or other space, but without safety guards or covers, they can expose rooftop workers to catastrophic falls, serious injury and death.

Atop a warehouse on Powers Avenue in Jacksonville, roofer John W. Miles III crashed through a skylight without an adequate safety cage and plunged more than 24 feet to the ground below. He was admitted to an area hospital in critical condition and later died of his injuries.

Employer name: Suburban Propane Partners LP

Site: Fort Worth, Texas

Date initiated: The Occupational Safety and Health Administration began investigating the propane gas facility in November 2014.

CALUMET CITY, Ill. — Workers at two Chicago-area Dollar Tree Inc. stores were exposed to safety hazards from blocked exit routes and boxes piled at dangerous heights. The national retailer, who recorded sales of $8.6 billion in 2014, has been cited by the U.S. Department of Labor's Occupational Safety and Health Administration for more than 200 safety and health violations across the nation since 2009.

Employer name: Allied Metals LLC

Inspection site: At the time of the inspection, workers were recycling metal at the company's warehouse located at 2902 NW 32nd Avenue, Miami, Florida 33142.

Date inspection initiated: The Occupational Safety and Health Administration initiated the Nov. 21, 2014 inspection as part of the agency's Site Specific Targeting Program.

BEAR, Del. — Boxes and excess merchandise could be a matter of life or death for workers at a Dollar General store in Bear, where federal inspectors found emergency exits blocked, in violation of federal law.

The review by U.S. Department of Labor Occupational Safety and Health Administration inspectors was done in November 2014 at the store at 1679 Pulaski Highway, where four violations were found. Proposed penalties total $122,100.

Employer name: Recycling Revolution LLC

Inspection site: 4190 Collins Rd., Unadilla, Georgia. 31091

Date inspection initiated: The Occupational Safety and Health Administration initiated the November 12, 2014 inspection as part of its National Emphasis Program on Amputations.

Investigation findings:

BRIDGETON, Mo. — A 31-year-old assembly technician was working with a battery charger manufacturer for about a month when tragedy struck. In November 2014, the man was testing transformers when he was electrocuted.

U.S. Department of Labor Occupational Safety and Health Administration investigators found that the man's death might have been prevented if his employer, Ferro Magnetics Corp., had supplied adequate personal protective equipment, followed safety procedures and provided training.

DORAL, Fla. — If you're a construction company owner and routinely choose to ignore worker safety, you may want to think twice about putting your employees in danger of falls and other serious safety risks.

Nine contractors at the newly constructed Oasis Park Square residential development in Doral learned a hard lesson when U.S. Department of Labor Occupational Safety and Health Administration inspectors visited the work site in November 2014.

ROTHSCHILD, Wis. — Workers welding stainless steel and other alloy steels containing chromium metal at a Wisconsin bulk storage tank manufacturer were exposed to hazardous levels of hexavalent chromium. At high levels, hexavalent chromium can cause lung cancer and respiratory, eye and skin damage.

CONCORD, N.H. — After record-setting snowfall last winter, New Hampshire residents scrambled to get heavy snow off their roofs to avoid damage. At the same time, U.S. Department of Labor Occupational Safety and Health Administration inspectors found contractors who ignored hazards and had employees remove snow from roofs without using required fall protection.

LAPORTE, Texas —Four workers killed by a lethal gas in November 2014 would be alive today had their employer, DuPont, taken steps to protect them, a U.S. Department of Labor investigation found.

Federal safety investigators find serious failures in 2014 toxic release in Texas

LAPORTE, Texas Four workers killed by a lethal gas in November 2014 would be alive today had their employer, DuPont, taken steps to protect them, a U.S. Department of Labor investigation found.

VANDALIA, Ill. — A metal tube manufacturer put workers at risk of lacerations, amputations and potential explosion and fire by ignoring standard safety rules for machines and storing flammable materials in open containers near propane heaters where they might ignite.

Employer name: DS Utilities Inc.

Inspection site: At the time of the inspection, workers were installing sewer lines at the intersection of Lee and Washington Roads, Fort Jackson, South Carolina 29207.

Date inspection initiated: The Occupational Safety and Health Administration initiated the January 2015 inspection as part of the agency's National Emphasis Program on Trenching and Excavation.

PROVIDENCE, R.I. — Inspectors from the U.S. Department of Labor's Occupational Safety and Health Administration were headed back to their Providence office on Jan. 22, 2015, after completing one site inspection when they saw a dangerous situation in clear view at another site in North Smithfield.

Participants: The Occupational Safety and Health Administration today entered into an alliance with the Associated Builders and Contractors of Greater Houston, American Subcontractors Associations-Houston Chapter, Gulf Coast Safety Institute of the College of the Mainland and the Scaffold and Access Industry Association to protect workers from exposure to fall hazards in the construction industri

BELLEFONTAINE, Ohio — A rubber-hose manufacturer in Ohio continues to put workers at risk of amputations and serious injuries by ignoring safety rules for industrial machines, U.S. Department of Labor Occupational Safety and Health Administration inspectors found after an October 2104 inspection.

Employer name: Americold, Atlanta, Georgia

Inspection site: Americold, 1731 Morrow Street, Green Bay, Wisconsin

Date investigation initiated and what prompted inspection: On Dec. 9, 2014, the U.S. Department of Labor's Occupational Safety and Health Administration's Appleton Area Office initiated an inspection of Americold's Green Bay, Wisconsin, refrigeration warehouse under the Site Specific Targeting 2014 National Emphasis Program.

HARTFORD, Conn. — Emergency exits blocked by piles of store inventory appears to be a recurring hazard at Forever 21. The fashion retailer's employees at Westfarms Mall in Farmington were among the chain's workers put at risk of not being able to exit the store swiftly because of fire or another emergency, U.S. Department of Labor inspectors determined after receiving a complaint.

NEW ALBANY, Ohio — When a 23-year-old diver descended to the bottom of a New Albany pond in November 2014, he thought his air supply would last during underwater work. He drowned when his air supply depleted while SCUBA diving.