A 'small hole' for example the size of a window or two is not likely to suck out a child unless he/she was next to it...
Unless the bomb and the toddler happened to both be in the rear toilet at the time. Which is a likely scenario.
And regard David Cameron going out on a limb with the bomb theory. One suspects that GCHQ has gone back through its records for the region and found some terrorist 'chatter'. (Not all information can be analysed in real time, because they do not have the staff for that, which is why data 'mining' will not effect Joe-public. They don't have the time or resources to read everything.)
But if some relevant 'chatter' had been uncovered, it would negligent to not act upon it, even if it was not actually the cause of this particular accident. So Cameron is between a rock and a hard place - he has to act even when the results of the investigation are not known.
Silver