Working in the oil patch can be dangerous.
Some of those dangers aren't visible to the naked eye. When workers open oil tanks to gauge levels, they can be surrounded by deadly gases.
At least nine people in Colorado, Texas and North Dakota have died from exposure to these gases. Inside Energy's Emily Guerin reports from North Dakota on how oil haulers have been dealing with this hazard.
https://www.youtube.com/watch?v=dA0u_EUTJrc
Inside Energy, a national hub for energy reporting, includes seven public radio and television stations from Colorado, Wyoming and North Dakota. Its reporting explores the points of tension, the tradeoffs and opportunities, and the very human consequences of energy policy, production, use and innovation.