The last two construction employers that I worked for were closed due to economical reasons. I have lost contact with my supervisors and some co-workers. I would really like to have a professional reference from some of these people. Any suggestions?

These days, don't leave your work home without collecting all the reference letters you can, even if you have to draft them yourself. And use time-honored moves, like keeping-in-touch telephone calls and Christmas cards, to maintain references through the years.
The cheapest ways to find former bosses and co-workers is tracking them through people who might know where they landed, using print telephone directories and clicking Internet resources.
The best thing to do is to maintain a squad of people who can enthusiastically confirm your qualifications and job history so the same people aren't contacted over and over. Ardor is elusive when someone is asked to say the same thing 100 times.