I think Richiev has put the finger on one of the ways the logline could be improved.? As it is, the logline is framed around elements of the threat.? I suggest it is better to frame it around what the characters do in response to the threat.? IOW: what becomes the objective goal in response to the threat?
Another way it could be improved would be to focus on one character in the family as the protagonist.? If you believe your story must have more than one protagonist (say the man and his wife), then I suggest for your consideration this useful article by Karel Segers on "Why You Should Steer Clear of Dual Protagonists" on how to effectively arrange their relationship in the overall story.
fwiw