I was contacted by an adjuster from Metro/Amtrak/MARC and they said they would take care of everything, why should I get a lawyer?

As in all such injury cases, the insurance companies and transit companies try and get out ahead of claims in order to minimize the amount that they pay for such claims. Unless you have experience pursuing these claims, it is very difficult to accurately understand what fair compensation should be. Further, there are often deadlines and notification requirements for claims against governmental and quasi-governmental entities. Failure to make appropriate notification of the right entity can take away your ability to make any claim. It is important to contact an attorney who is experienced in such matters to ensure that all proper notifications are made.