Publicly, Lafarge painted a better picture of the dire event. The factory had been seized by ISIS, the company announced in a news release at the time, but Lafarge had succeeded in evacuating all of its remaining people.

But officials acknowledged to French investigators that the remaining Syrian employees had to flee on their own. Mr. Jolibois said Lafarge did not expect the situation to deteriorate so rapidly. “For what it’s worth, in another cement factory that didn’t belong to Lafarge, ISIS beheaded about 50 employees,” he told investigators.

In its statement to The Times, LafargeHolcim said Lafarge Syria “maintained its operations as long as the plant and its employees could remain secure.” It added that former employees were put on paid leave for more than 12 months after the closing of the site.

The money has not assuaged the Lafarge employees who believed they were scrambling to save their own lives in those final hours at the factory. Many were angered when Mr. Jolibois sent them an upbeat message shortly after the evacuation.

“Probably the things did not run perfectly or as good as planned, but nevertheless we achieved this key goal,” he wrote, according to an internal Lafarge email seen by The Times. “Lafarge Cement Syria is not dead. I am convinced that we will win the final battle.”

As a response, one of the survivors sent a follow-up email to Lafarge officials on behalf of other employees, denouncing Mr. Jolibois’s message as “full of lies.”

In it, the employees asked Lafarge to carry out an internal investigation into why workers were left to fend for themselves as ISIS advanced.

The employees said that the Lafarge officials never responded.

“The factory was the only thing they cared about,” Mr. Mohamad said. “But Lafarge should be a lesson for Western companies in foreign countries: They should treat people working for them like human beings.”