Refugio (ray-FYOO'-ee-oh) County authorities say the accident happened Tuesday afternoon at a Southcross Energy Partners plant near Woodsboro.
Justice of the Peace Lorraine Lopez says two of the men were in a hole repairing a gas pipeline when a piece of the line came loose, releasing about 800 pounds of pressure. The victims were blown from the hole.
Officials say one man died at the scene. Another died at a hospital. The third man was being treated at a hospital.
Messages left with Dallas-based Southcross were not immediately returned Wednesday.