Who passed the Debt line at Lost Alpha, tell me! (STALKER: Shadow of Chernobyl)

When passing the line of tasks for the DEBT, they are given the task to help the assault group at the construction site, when we arrive there we find a group surrounded by chimeras, interrupt them, then the survivors say that there are several more guys who were squeezed by mutants at the construction site, we come and see two long-timers and two yellow dwarfs. I replayed several times, but every time the debt workers are killed, is it generally possible to go through so that they would remain alive?