On June 8, 1990 at approximately 2330,
while the Italian tank vessel Fraqmura was lightering the Norwegian tank vessel Mega Borg,
an explosion occurred in the pump room of the Mega Borg.
The two ships were in the Gulf of Mexico,
57 miles southeast of Galveston Texas in international waters,
but within the U.S. exclusive economic zone.
As a result of the explosion, a fire started in the pump room and spread to the engine room.
An estimated 100,000 barrels of Angolan Palanca crude was burned
or released into the water from the Mega Borg during the next seven days.
Approximately 238 barrels of oil was discharged
when the Fraqmura intentionally broke away from the Mega Borg.
Explosions on the Mega Borg, caused the stern of the ship
to settle lower in the water and list to the port side.
A continuous discharge of burning oil flowed over the aft port quarter of the ship.
Less than an hour after the explosions on the Mega Borg,
the U.S. Coast Guard (USCG) in Galveston dispatched two USCG cutters to the scene.
Weather was calm throughout the incident.
Winds were generally around 10 to 15 knots
and air temperature were between 80 and 90 degrees Fahrenheit.
Palancan crude oil has an API gravity of 38.6, and a pour point of 50 degrees F.
Responders believed that abnormally high freshwater runoff
from the Sabine River and other rivers in the area would have a tendency to keep the oil offshore.
Initially the oil moved northwest toward Corpus Christi.
By June 18, the leading edge of the oil slick approached the environmentally sensitive area of Sabine Pass,
but was kept offshore by winds and currents.
After a few days it began to move to the north and east
and first came ashore on the Southwestern Louisiana coast on June 28
in the form of small tarballs scattered over a distance of 18 miles.
Shorelines that suffered oiling included Holly Beach and Dung Beach in Texas,
Peveto Beach in Louisiana, and the Mermentau River in Louisiana.
The tarballs on the shoreline amounted to very little oil.
The floating oil spread out into a light sheen.
Much of the spilled crude oil was lost to evaporation (as much as 50%) or burned.
Overflight observations generally noted light sheen on the water mixed with tarballs.
A small amount of reddish colored mousse was also observed.
The initial focus of the response effort was
to extinguish the fire on the Mega Borg and offload the remaining cargo.
Firefighting vessels began to arrive on the morning of June 9.
Over 50 commercial vessels and more than a dozen skimmers were used during the response.
In addition, a USCG Air-Eye aircraft, equipped with side looking airborne radar (SLAR),
was used to determine the distribution of the spilled oil.
Two more explosions occurred on board the Mega Borg on June 9.
The fire was fueled by cargo from the No. 4 tank which was leaking into the engine/pump room.
Initially, the vessel was so hot that it was feared
that the application of foam to extinguish the fire
might be ineffective or increase the possibility of explosion.
Firefighters cooled the hull of the ship
and attempted to prevent the fire from spreading to the other cargo tanks.
Six vessels were used to fight the fire.
Four of the vessels hosed the Mega Borg with seawater in attempts to contain the fire and cool the vessel,
and the other two vessels, which were equipped for foam application,
kept the burning stern of the Mega Borg downwind.
Pump valves on the Mega Borg were secured (hydraulic block valves were operated manually)
on 10 June in an attempt to stop the flow of oil.
The oil continued to flow from the tanker,
and later that day there were a series of new explosions on board.
The explosions intensified the fire and caused the stern of the Mega Borg to become partially submerged,
increasing the risk that the tanker would sink and release the remainder of its cargo.
By June 13, firefighting efforts had contained the blaze sufficiently to attempt foam application.
The fire was out for almost an hour and a half
while the foam was being applied, but then re-ignited.