[4] The day before Ixtoc suffered the blowout and resulting fire that caused her to sink, the drill bit hit a region of soft strata.

During the removal of the pipe on Sedco 135, the dancing mud suddenly began to flow up towards the surface; by removing the drillstring the well was swabbed (an effect observed when mud must flow down the annulus to replace displaced drill pipe volume below the bit) leading to a kick.

The oil and gas fumes exploded on contact with the operating pump motors, starting a fire which led to the collapse of the Sedco 135 drilling rig riser.

Pemex claimed that half of the released oil burned when it reached the surface, a third of it evaporated, and the rest was contained or dispersed.

[6] In Texas, an emphasis was placed on coastal countermeasures protecting the bays and lagoons formed by the barrier islands.

Impacts of oil on the barrier island beaches were ranked as second in importance to protecting inlets to the bays and lagoons.

Pemex spent $100 million to clean up the spill and avoided most compensation claims by asserting sovereign immunity as a state-run company.

[12] The oil slick surrounded Rancho Nuevo, in the Mexican state of Tamaulipas, which is one of the few nesting sites for Kemp's ridley sea turtles.

Thousands of baby sea turtles were airlifted to a clean portion of the Gulf of Mexico to help save the rare species.

The oil that was lost during the blow-out polluted a considerable part of the offshore region in the Gulf of Mexico as well as much of the coastal zone, which consists primarily of sandy beaches and barrier islands often enclosing extensive shallow lagoons.

Based on reports from various groups and individuals, five times that figure is thought to represent a fair estimate of what had landed on Mexican beaches.

[14] The oil washed ashore, 30 cm (1 ft.) deep in some places, as it was pushed north by prevailing winds and currents until it crossed the Texas border two months later and eventually coated almost 170 miles (270 km) of US beaches.

The beach that caused most international concern in Mexico was Rancho Nuevo, a key nesting ground for critically endangered Kemp's ridley sea turtles which had already moved inland in their hundreds to lay eggs.

Despite a massive intrusion of petroleum hydrocarbon pollutants from the Ixtoc 1 event into the study region of the South Texas Outer Continental Shelf during 1979-1980, no definitive damage can be associated with this or other known spillage events (e.g., Burmah Agate) on either the epibenthic commercial shrimp population (based on chemical evidence) or the benthic infaunal community.