Dreams involving death, especially in a workplace setting, can be quite intense and unsettling. Here are some interpretations that might help you understand the symbolism behind your dream:

1. Fear of Loss: The dream may reflect a fear of losing your colleagues or the stability of your work environment. It could symbolize anxiety about changes in your job or the dynamics within your team.
2. Survivor's Guilt: Being the only ones left could indicate feelings of guilt or concern about why you survived while others did not. This can often point to feelings of inadequacy or questioning your own worth in a group setting.
3. Transformation: Fire often represents transformation or change. This dream might signify that you are going through a significant change in your professional life, and it could be an invitation to reflect on what changes are occurring and how they affect you.
4. Isolation: The dream could also indicate feelings of isolation or being overwhelmed in your work environment. It may suggest that you feel alone in facing work-related challenges.
5. Concern for Colleagues: If you have been worried about a colleague or the overall atmosphere at work, this dream might be a manifestation of those concerns.

Take some time to reflect on your current feelings about your work situation and your relationships with your colleagues. It may also be helpful to talk to someone you trust about these feelings to gain further clarity.