Helfend (P) was injured when his car collided with an R.T.D. (D) bus. Some of P's medical bills were paid by his medical insurance. P sued D for personal injuries. P claimed $2,700 in special damages including $921 in doctor’s bills, a $336.99 hospital bill and about $45 for medications. D offered P's medical insurance payments to mitigate its own liability. This evidence was not allowed. P was awarded a judgment for $16,400 in general and special damages. D appealed; recovery from a collateral source should be admissible.