Suncor Energy Inc.’s chief executive officer stepped down on Friday after a series of fatalities at the company’s oil sands sites shook confidence in its management. 

Mark Little agreed to step down as president and CEO and resign from the board of directors “effective immediately,” the company said in a release. Kris Smith, executive vice president for downstream, has been named interim CEO.

Little’s resignation came a day after a worker was killed at Suncor’s Base Plant mine in northern Alberta, the latest in a series of accidents that has prompted calls for change. 

“Suncor is committed to achieving safety and operational excellence across our business, and we must acknowledge where we have fallen short and recognize the critical need for change,” Board Chair Michael Wilson said in the release.

In April, Suncor investor Elliott Investment Management LP called for five directors to be added to the producer’s board and sought a management review after operational mishaps and accidents at its oil-sands projects caused the company to miss production targets. Elliot Investment said in an email Friday that it had no comment. 

A truck accident in January killed a contractor and injured two others at the Base Plant mine. In June of last year, a person was killed at the Syncrude mine, and two deaths occurred in December 2020 at the Fort Hills mine. 

Suncor’s safety record has been a contributing factor to its poor investment returns. Over the past two years, the company’s share price has risen less than the four other major Canadian oil sands producers Cenovus Energy Inc., Canadian Natural Resources Ltd., Imperial Oil Ltd. and MEG Energy Corp.

Suncor’s board has formed a committee to carry out a global search for the next CEO, the company said. External and internal candidates will be considered for the role.

Little took over leadership of the Canadian energy giant three years ago, replacing Steve Williams. He steered the company through the pandemic, when oil demand collapsed and West Texas Intermediate futures prices briefly went negative. 

Covid-19 also posed unique operational challenges for oil sands producers such as Suncor, which struggled to stem the rapid spread of the virus among thousands of workers often living and working in close quarters in remote camps. 

Little also tried to improve his company’s image within the investment community by focusing, along with other oil sands producers, on reducing the industry’s carbon emissions.