11:30 here in los angeles. police in berlin, treating a truck crash as a terror attack. the tractor went into a crowd. some of the images you're about to see are graphic and disturbing. this is cell phone video moments after the attack. police arrested one man, not far from the crash side. a dead passenger found inside the truck was a polish citizen. >> reporter: from berlin, here's fred pleitgen. they say they have one man in custody. at this point in time, they are not sure what the nationality of the man is. and they cannot be certain that this is the same person of the wheel at the tractor-trailer as it plowed through the christmas market here on monday night.