During construction implementation, a key supplier went bankrupt and cannot deliver contracted materials, potentially impacting the schedule. What should the project manager do first?

The correct answer is to update the issue log and take actions to minimize the impact. The supplier bankruptcy is no longer a potential risk; it's an actual event that has occurred, making it an issue. The project manager must document this in the issue log and immediately work to mitigate its effects, such as finding an alternative supplier or expediting other tasks. Escalating to management (option A) might be necessary later, but the project manager should first analyze the situation and propose solutions. Recording it in the risk register (option B) is incorrect because it's no longer a risk but an issue. Updating the schedule (option C) is premature; the project manager needs to determine the actual impact and mitigation strategies before adjusting the schedule.