A contractor was killed and two others were injured Saturday morning while working on a Chevron natural gas pipeline off the coast of Lousiana. Two other workers sustained minor injuries.

News sources indicated that the workers were performing maintenance on the platform, which is part of a natural gas gathering system, when the accident occurred.

A spokesman for Chevron said the cause of the accident is under investigation and that containment crews were dispatched to the platform. Natural gas is being released at the platform to relieve pressure on the line owned by Chevron Midstream Pipeline LLC. The spokesman said some natural gas condensate was released into the water, but dissipated.

The identity of the contractor was not released.