(Gaston, OR)  --  Two people are injured after a tractor crashed on top of their car, trapping them inside.  Authorities say the two were traveling north on Front Street in downtown Gaston when their car clipped an oncoming tractor, causing a second tractor to run over them.  The two were trapped inside their crushed car underneath the tractor for about two hours before rescue crews were able to get them out.  Authorities say their injuries range from minor to serious and that they're lucky to be alive.