Federal safety records show 10 workers have died over the past decade at well sites linked to drilling contractor Patterson-UTI, the same driller involved in this week's rig explosion in Oklahoma that killed five workers.
An analysis of Occupational Safety and Health Administration data shows the previous accidents happened at drilling sites in Colorado, New Mexico, North Dakota, Pennsylvania and Texas.
The company also was fined nearly $367,000 over the past 10 years for more than 140 safety violations.
Houston-based Patterson-UTI said in a statement it has embraced safety improvements and spent millions of dollars in recent years on worker training and protective equipment.
Monday's blast appears to be the deadliest oil and gas industry accident since the 2010 Deepwater Horizon explosion off the Louisiana coast that killed 11 workers.