CNN CNN Newsroom Live August 25, 2015 05:43:00
Ever since it opened 21 years ago, connecting london with paris and brussels, it's been considered that the channel tunnel is a target. and therefore, you've always had airport-style security. and because there's so few stations involved in the network, that's been relatively easy to maintain. >> reporter: but the eurostar is a tiny part of the rail network. long sections of high-speed rail weave through a complex web of local city and rail lines. it moves hundreds of millions of people per year with little to no passenger screening. >> it is the sorts of numbers which simply don't happen in a...