The 15-month commodities free-fall is starting to resemble a full-blown crisis.

Investors are reacting to diminished demand from China and an end to the cheap-money era provided by the Federal Reserve. A Bloomberg index of commodity futures has fallen 50 per cent since a 2011 high, and eight of the 10 worst performers in the Standard & Poor’s 500 Index this year are commodities-related businesses.

Now it all seems to be coming apart at once. Alcoa Inc., the biggest U.S. aluminum producer, said it would break itself into two companies amid a glut stemming from booming production. Royal Dutch Shell PLC announced it would abandon its drilling campaign in U.S. Arctic waters after spending $7-billion. And the carnage culminated Monday with Glencore PLC, the commodities powerhouse that came to symbolize the era with its initial public offering in 2011 and bold acquisition of a rival in 2013, falling by as much as 31 per cent in London trading.

“With China slowing down and a lot of uncertainty, fears in the market have intensified, and the reduction in the pace of demand growth for all commodities has seemed to send everybody off the cliff,” said Ed Hirs, managing director of a small oil producer who teaches energy economics at the University of Houston.

Peak prices in gold and silver are four years old, oil’s plummet since June 2014 has been pushed along by OPEC’s November decision to keep pumping despite excess supply and U.S. natural gas prices have fallen to less than a fourth of their 2008 value.

It’s about to get worse, according to analysts John LaForge and Warren Pies of Venice, Florida-based Ned Davis Research Group. Commodities may be in the fourth year of a 20-year “bear super-cycle,” according to an Aug. 14 research note. The analysts looked at commodity busts dating to the 18th century and found them driven by factors such as market momentum rather than fundamentals, LaForge said Monday in an interview.

The good news: most of the damage is done in the first six years, LaForge said.

“In commodities you’re going to get a lot of failures, companies closing up,” he said. “This needs to happen to bring down supply.”

A debt-reduction strategy announced three weeks ago by Glencore Chief Executive Officer Ivan Glasenberg and a plan to sell a stake in its agricultural unit failed to stem the bleeding. Investec Plc warned Monday that there is little value for equity shareholders if low raw-material prices persist.

After a failed Arctic exploration campaign that cost $7-billion and was targeted for years by environmentalists, Shell will be forced take financial charges related to the Alaskan operations, which carry a value of about $3-billion, with additional contractual commitments of about $1.1-billion.

Alcoa will separate its manufacturing operations from a legacy smelting and refining business that’s struggling in the face of booming output from China.

Even so, profits at Chinese industrial companies plunged 8.8 per cent in August from 12 months earlier, with losses deepening even after five interest-rate cuts since November and government efforts to accelerate projects.

The ripple effects of the pain have seeped farther into the corporate world. Caterpillar Inc. said last week that it would cut as many as 10,000 jobs, or 9 per cent of its work force, as the persistent oil rout made the mining slowdown worse. Chemical maker Huntsman Corp. fell the most in four years after saying lower titanium prices would have a negative impact on third– quarter earnings.