5 missing in Oklahoma oil rig explosion now presumed dead

QUINTON, Oklahoma (KTRK) -- Officials say five employees missing after Oklahoma rig explosion are presumed dead. The company pledges full investigation.

The blast happened Monday morning at a drilling site near Quinton, about 100 miles southeast of Tulsa.

Houston-based company Patterson-UTI Energy owns the rig. They are pledging a full investigation into what happened.

The explosion sent plumes of black smoke into the air and left a derrick crumpled on the ground. For much of the day Monday, emergency officials were unable to get near the rig because the fire was still burning.

Emergency management officials said Monday night that the fire was extinguished.

Authorities say 16 people who were on the site at the time of the blast escaped without major injuries. One person was airlifted to a hospital, and five others remain missing and are presumed dead.

Three of the people involved are reported to be from Houston.

The cause of the blast is not yet known.

The Associated Press contributed to this report.