A Boeing 767-200 and 200ER have a maximum takeoff weight of 315,000 and 395,000 pounds, respectively. They cruise at a speed of 530 miles per hour. A B-25 has a maximum takeoff weight of 35,000 pounds and a cruising speed of 272 miles per hour. A 767-200ER hits win an impact 36 times greater than a B-25, and would actually have to be at 90 miles per hour to have similar kinetic energy. I'm pretty sure that's well below stall speed, so the impact energy is likely to be much higher. In any case, even if an aircraft of similar weight hit at a similar speed the results might be different because a B-25 used more steel and sturdy construction in its design than modern aircraft and used aviation gas instead of jet fuel.