WILLISTON, N.D. – Spencer Logan was in Hour 16 of his day as a Halliburton safety lead on a hydraulic-fracturing site. It was raining, cold and "the site was just a mud hole and I was just concerned about getting the hell out of there."

He failed to look up and see a wire line still on, which should have prompted him to open a value and release 4,500 pounds of pressure. The screw-up left live explosives — known as guns — 4 miles down in the ground, costing his company "lots of money" and nearly getting him fired after four years working his way up the Halliburton ladder.

"I was in too big a hurry," said Logan, 45, who grew up in Red Wing and lives in California when he's not fracking for oil in North Dakota.

He's just glad no one got hurt.

"There are chemicals and explosives, lots of high pressure and so many different things that can get you killed that you'd better know what you're doing before you step on a site."

Of the 70 death investigations the Occupational Safety and Health Administration has conducted in North and South Dakota since Oct. 1, 2009, more than half (37) have stemmed from the oil fields of western North Dakota.

Tom Wallace — DML - Star Tribune, Star Tribune
Spencer Logan, a fracking site safety lead for Halliburton, was present when a Duluth man was killed at a fracking site and described what happened.

Logan remembers one of those deaths with an overwhelming tinge of sadness.

Mike Krajewski, a 49-year-old father of three daughters from Duluth, was killed when a pipe from a high-pressure line fell and struck his head while fracking in January. OSHA fined Halliburton $14,000 — the first time the oil-field servicing giant has been cited with workplace safety violations in North Dakota.

"I always wondered why he just didn't look up," recalled Logan, who witnessed what he called a "tragedy." He knew Krajewski personally as "a great friend.

"He thought it was time to go out there and bleed off the fluid from the joints so it would slowly flow out," Logan said. "He just didn't look up and see the wire line on there. It's all about being in a hurry. The thing flew up like a rocket as soon as he opened it up, and he got flown into the wellhead and it crushed the back of his head.

"It's just a reminder how dangerous this work can be."