Well, if the man was trapped, them he'd just mark out his options and find the right solution.
•Windows (must be checked if closed shut.)
• Weapons. You can use weapons to open the door, break the windows, ect.
There are many more options, but once you see your surrounding, you must make a technique.
Now, the man could always check the door if it's locked. For example, if it was a false alarm.
Then, I suggest the man to find a phone, or anyway to comminute to people outside of the building.
Then, if not he mist mark everything out and use his surroundings as his source.
Ask yourself, what do you have?
