An oil tanker carrying nearly a million barrels of ultra-light crude oil burned for days in the East China Sea before sinking on Jan. 14, killing all 32 crew members.

Now, the disaster threatens to become the worst oil spill in 35 years, according to a report Friday by Reuters — potentially devastating reefs and fishing grounds and polluting seafood from the region.

The Iranian tanker Sanchi crashed into the South Korean freight boat CF Crystal, which was carrying U.S. grain, on Jan. 6, according to The Washington Post. It burned for days afterward, releasing thick plumes of dark black smoke and frustrating international rescue efforts that included the U.S. Navy.

The ship was carrying 34 million gallons of ultra-light condensate — a form of oil that is extremely toxic, highly flammable, and difficult to detect, according to The Post.


“It’s not like crude, which does break down under natural microbial action,” Simon Boxall, of the the University of Southampton’s National Oceanography Centre, told the BBC. “[T]his stuff actually kills the microbes that break the oil down.”

Officials had hoped they could put out the fire before an explosion caused the ship to sink, according to the BBC. On Jan. 13, a Chinese rescue team briefly boarded using a suspension hook. They were able recover two bodies along with the black box before intense heat and toxic fumes forced them off the ship.

“The scenario was the worst I’ve ever seen,” rescuer Xu Zhentao told the Chinese TV network CGTN.

Despite these efforts the ship sank after an explosion around noon on Jan. 14. In Tehran, families of the trapped crew members who had gathered at National Iranian Tanker Company headquarters were devastated by the news, with CBS News reporting that some had to be rushed to the hospital for shock.


TV cameras recorded angry family members criticizing Iranian government officials for what the families said was a slow response to the disaster.

“Thirty-two people died without a funeral and without coffins,” one family member shouted at officials, according to the French outlet Euronews. “They burned to ashes while their families are wailing here. You, the government, have come after ten days to sympathize with them? What sympathy are you talking about?”

Meanwhile, experts worried about how much toxic condensate was left onboard the ship.

“The key issue is how much exactly the condensate oil has been left after all the burning and explosion, and how much of that sank together to the bottom of the sea,” Ma Jun, director of the Institute of Public and Environmental Affairs in Beijing, told CBS News after the ship sank.

Researchers previously thought the spill would remain offshore. But a new report released Jan. 16 by the University of Southampton’s National Oceanography Centre, in Southampton, England, shows the impact could be much greater than previously thought.

“An updated emergency ocean model simulation shows that waters polluted by the sinking Sanchi oil tanker could reach Japan within a month,” the report said. “The revised simulations suggest that pollution from the spill may be distributed much further and faster than previously thought, and that larger areas of the coast may be impacted.”


The size and impact of the spill are still uncertain. South Korean officials believe the light crude condensate will evaporate, according to Reuters. But the heavier fuel oil from the tanker could pose a more serious threat, and the new models released Jan. 16 raise concerns. Japan’s Fisheries Agency told Reuters it is closely monitoring the situation.

The 34-million-gallon spill is three times larger than the infamous Exxon Valdez spill off Alaska in 1989, which spilled around 11 million gallons. But, as The Washington Post reported, it pales in volume-comparison to other oil spills. The Deepwater Horizon disaster, for example, spilled 210 million gallons into the Gulf of Mexico in 2010.

“Oil spills can have a devastating effect on the marine environment and on coastal communities,” Katya Popova, lead researcher on the National Oceanography Centre report, said on the group’s website. “Strong ocean currents mean that, once released into the ocean, an oil spill can relatively rapidly spread over large distances.”

CORRECTION: An earlier version of this story incorrectly stated the size of the Deepwater Horizon spill. It was 210 million gallons.