inside a crash test that could have you thinking twice. reporter: once a stretch limo, now all that remain, a mangled mess of metal. this is a crash test simulation. but in july of 2015, four women were killed when their limo crashed in long island, new york. last october, a birth celebration in upstate new york turned tragic in this stretch limo accident. in all, 20 people killed including four sisters and 2 procedures. the most deadly transportation accident in the u.s. in almost a decade. but what is it that makes limo accidents especially dangerous? to show you what happens when a stretch limo like this crashes with dummies inside, we are at cape, one of the leading crash tests facilities for commercial vehicle, and this is nick, head engineer here. nick, what are we seeing today? looking for how the passengers fare in this test