I imagine they do consider eventualities, but some things are extremely unlikely. Could someone set off a nuclear bomb under the bridge? Sure. Is it likely? No. Could a tanker truck full of gasoline catch on fire and sit directly under this bridge? Yes. Is it likely? No.
It’s generally a good idea to look into events a tad more than just reading a headline before running around posting about them.
This is especially true when the headline seems to confirm one’s beliefs about something. In fact, most of the USA’s problems if not the worlds are in a big part due to people having that level of engagement.