The explosion cut through the Patterson-UTI rig just before 9 a.m. Monday. More than 20 people were working at the well site when the explosion occurred west of Quinton, about 100 miles southeast of Tulsa, authorities said.

Authorities said 16 people escaped the explosion without major injuries. One person was airlifted to a hospital. The fire was extinguished Monday night.

The intense fire had prevented investigators from getting to the scene to confirm any fatalities. Authorities earlier searched the surrounding woods to see if anyone had fled into the area. Aerial footage showed several fires were still burning by midday Monday on the rig and much of the equipment had collapsed to the ground.

Patterson-UTI has about 25 drilling rigs active in Oklahoma, second only to Texas, where it has nearly 60 rigs in operation.

The incident occurred at the site of one of Patterson-UTI’s more modern APEX 1500 rigs, described as a “light, safe, and efficient rapid deployment rig.”

This article first appeared on the Houston Chronicle – an Energy Voice content partner. For more from the Houston Chronicle click here.