SAO PAULO (Reuters) - Brazilian miner Vale SA’s shares plunged on Monday, wiping out 71.34 billion reais ($18.96 billion) in market value, after a tailing dam collapse on Friday killed scores of people at one of its mines, less than four years after a similar disaster.

Members of a rescue team search for victims after a tailings dam owned by Brazilian mining company Vale SA collapsed, in Brumadinho, Brazil January 28, 2019. REUTERS/Adriano Machado

Vale shares fell 24 percent to close at 42.65 reais, their steepest daily drop ever in percentage terms. Brazil’s stock market was closed on Friday when the disaster occurred. Vale’s ADR fell 8.1 percent on Friday and 18 percent on Monday, to close at $11.20, the lowest close since December 2017.

Prosecutors, politicians and victims’ families called for punishment, as fears grew that the death toll from the disaster, already 65, could soar into the hundreds. Fines, lawsuits and a regulatory crackdown were expected. The company suspended dividend payments late on Sunday.

“The fact is that Vale’s share drop was even steeper than some market participants expected,” said Igor Lima, a fund manager and partner at Galt Capital in Rio de Janeiro.

“At the same time, the reaction of the government and other public agencies has been quite a bit stronger than in the Samarco accident,” he said, referring to a 2015 mining dam burst involving a Vale joint venture. “This reaction has brought quite a lot of uncertainty about the size of the financial punishment Vale will have to handle.”

Brazil’s top prosecutor, Raquel Dodge, said the company should be criminally prosecuted. Executives could also be personally held responsible, she said.

HSBC and Jefferies have already cut their recommendations for the shares to hold from buy. Other analysts have held back, saying they are trying to figure out potential damages. A law firm filed a class-action lawsuit against Vale and its top executives in a New York court.

GREATER SCRUTINY?

Previ, Brazil’s largest pension fund and a major shareholder at the mining company, said in a statement that it could absorb the impact from the steep share price drop without the need to eventually sell any of its holdings.

“Billions of dollars in Vale’s assets have already been frozen as we discussed this weekend,” said Michael Underhill, chief investment officer at Capital Innovations LLC in Milwaukee, adding that the lost production from the affected mine could be made up elsewhere in Vale’s system.

“There remains a fair chance that all of Vale’s dams (which exceed 100 in count) will also be coming under great scrutiny going forward,” said Underhill.

Vale bond prices also fell, with the yield on its August 2026 bonds jumping to 5.7 percent from 4.6 percent early on Friday before the dam bust, according to Market Axess Bondticker.

Fitch downgraded the company’s debt on Monday to BBB- and placed it on ratings watch negative. Late on Friday, Standard & Poor’s put Vale’s debt under review for possible downgrade.

So far, Brazilian courts have issued orders to freeze 11.8 billion reais ($3.1 billion) in Vale’s accounts to cover rescue efforts and damages. The company had around 24 billion reais in cash and equivalents at the end of the third quarter.

Analysts at Credit Suisse said in a note to clients they anticipated regulatory changes for tailings dams because it was the second disaster in less than four years, after the fatal 2015 dam burst at Samarco Mineracao, a joint venture by Vale and BHP Group.