Financial crises can happen quickly, like the bursting of the tech stock bubble in early 2000, or slowly, like the late-1980s junk bond bust. The shape of the crash depends mostly on the asset in question: Equities can plunge literally overnight, while bonds and bank loans can take a while to reach critical mass.

China’s bursting bubble is of the second type. During its post-2009 infrastructure binge, trillions of dollars were lent to (way too many) producers of cement, steel, chemicals and other basic industrial inputs. And now a growing number of them can’t make their payments:

China’s Bond Stresses Mount as Two More Companies Flag Concerns

A Chinese fertilizer maker and a pig iron producer have flagged bond payment difficulties, adding to signs of stress in the nation’s corporate note market after at least six defaults this year.

Jiangsu Lvling Runfa Chemical Co., based in the eastern city of Suqian, is asking its guarantor to repay 53.1 million yuan ($8.3 million) in bond principal and interest due Dec. 4, according to a statement posted on Chinamoney’s website. Sichuan Shengda Group Ltd., based in the southwestern province of Sichuan, is uncertain it can repay notes due in 2018 that holders can opt to sell back early on Dec. 5, it said in a statement on the same website Thursday.

More companies in China are struggling to repay bonds amid the worst economic slowdown in a quarter century. China Shanshui Cement Group Ltd. this month became at least the sixth company in 2015 to default on yuan-denominated domestic notes. State-owned steel trader Sinosteel Co. postponed a bond payment for a second time last week.

The guarantor of Jiangsu Lvling Runfa’s bond is Jiangsu Re-Guarantee Co. The bonds are so-called collective notes, which are typically issued by several small- and medium-sized companies that don’t have the ability to sell securities on their own. A filing earlier this week didn’t specify the other issuers of the 6.2 percent notes that have a face value of 100 million yuan.

Bank of Tianjin Co., the trustee manager on Sichuan Shengda’s notes, said it will hold a bondholder meeting on Dec. 3, according to a statement to Chinamoney Thursday. Sichuan Shengda’s subsidiary’s pig iron production is in halt because of falling prices and the cash shortage, the lender said in a separate statement.

Sichuan Shengda and its subsidiary had a total of 514.41 million yuan of overdue borrowings as of Nov. 25, according to Bank of Tianjin’s statement.

The stress isn’t limited to bonds. China Fishery Group Ltd. failed to repay a $31 million installment due earlier this month on a $650 million loan, according to Standard & Poor’s. Creditor banks may have found it difficult to roll over the debt following a government investigation the company flagged in August, according to JPMorgan Chase & Co.