I was hurt working in a restaurant and get tips in addition to my regular wages. Are tips included in the average weekly wage and can I get workers comp benefits based on tips?

Absolutely - but you need to have a record of the tips you earned.  Sometimes the restaurant or bar will keep a record in their point of sale or cash out sheets, but you should keep a separate record of all the tips you earn so you can prove your total income.

Occasionally, a worker will have a serious injury on the job in D.C., and was making a lot of money in tips but not reporting or declaring the tips.  If that's the case, the workers comp benefits won't be based on the tips and there will be no way to realistically prove how much they actually earned - plus they may have problems with the IRS...

Remember, the average weekly wage is fixed as of the date you get hurt at work in D.C. and you go back 6 months and include all income during that time - overtime, bonuses, salary, tips, etc. and average it.  The higher the average, the higher the workers comp benefits you'll get when you can't work because of the injury.