Corrected entry: Just after the Prometheus destroys itself by driving into the alien ship, the alien ship lands on the ground and the ship starts falling onto Elizabeth and Meredith. They start running directly away from the ship as fast as they can, but in exactly the same direction in which it's falling. If they had ran in literally any other direction, they would be perfectly safe within seconds.
Casual Person
1st Nov 2013
Correction: There is no way they could have known the ship was going to "roll" in that direction. We only know this in hindsight. The ship could have easily fallen sideways and the direction they ran would have worked out.
XIII