I was wondering about the trunks, too. It looks as though the water pushed through the cars and popped them open. I thought it was interesting that the trunks on the shore side were more open than the ones across from them. Perhaps a difference in wave action or wind direction.
This is something I've always wondered about and now I have confirmation.
From a website:
Floods can be both a cause of or an effect of an earthquake.
Flood water places an extra hydrostatic pressure on unstable and
mobile crustal blocks. If this extra pressure reaches the
threshold strain limit along a fault zone or plate boundary within
the Earth's crust, it can cause an earthquake to occur due to a
sudden release of the strain energy accumulated over time.
Similarly, an earthquake can change the surface drainage pattern
and consequently the course of a river, causing sudden flooding in
an area. Even though the cause and effect relationship between
floods and earthquakes is not very clear, historic records suggest
a relationship between these two phenomena. (http://www.cs.albany.edu/~amit/BanglaFloods.txt).
Scary thought. New Orleans isn't all that far away from the New Madrid fault!