Four workers were hospitalized, two of them in critical conditions, after an explosion at a St. Louis trucking terminal on Aug. 6, 2014. The explosion's cause: a forklift's ignition source and a loose coupling connection to a liquid propane gas tank. An investigation of the incident by OSHA resulted in one willful and 11 serious safety and health violations at Saia Motor Freight Line LLC, with proposed penalties of $119,000.

How it happened

OSHA inspectors found that two forklift operators were changing a propane tank on a liquefied petroleum gas-powered forklift inside a freight trailer when a loose coupling connection permitted liquid propane to leak, vaporize and ignite, causing a flash fire. Both a 54-year-old lead forklift operator and a newly hired 25-year-old worker, who had used propane forklifts for about a month, received critical burns. A third worker suffered burns to his legs as he helped extinguish his colleagues' burning clothing. A fourth employee, who was using his forklift near the flash fire, was also burned.

"Workers must be trained to avoid deadly combinations of flammable fuels, ignition sources and confined spaces, which allow vapors to ignite quickly," said Bill McDonald, OSHA's area director in St. Louis.

Inspectors found several powered industrial trucks with defective or bypassed safety switches being used when they were in need of repairs.

Hazmat dangers

Many of the violations involved propane hazards. OSHA found that Saia did not evacuate the work area after the release of the flammable gas; require the exchange of forklift propane containers in an adequately ventilated area; mount gas containers on the cylinder indexing pin correctly; train workers on extremely flammable gas hazards; and require the use of hand and eye protection when changing cylinders. Additionally, hazardous chemicals in the maintenance shop were not labeled. The company also failed to train powered industrial truck operators, and several electrical safety hazards were noted.

Based in Duluth, Georgia, Saia has 147 terminals covering 34 states and Canada. It employs approximately 8,000 workers. There are three operating service groups: Saia LTL, Saia Truckload Plus and Saia Logistics Services. The company has about 150 employees at the St. Louis terminal who perform cross-dock operations.

From the Saia website:

"By cultivating an environment that promotes physical safety as well as professional success, Saia ensures that our customers get our very best every day. Safety starts with each employee understanding the indispensable role he or she plays in our shared success. It demands attention to detail – on the dock and on the road – and a willingness to be absolutely vigilant regarding actions or conditions that could result in a workplace accident. At Saia, our safety record stands on its own; built by caring individuals who see safety as the responsibility of everyone."