A snow covered street with people walking.
The snow is starting to turn to ice.
Snow turns to ice from moisture or from melting in high humidity and low temperature, not from people walking on it.
exists e1 e2 x1 x2 x3.(Actor(e2,x3) & v_walk(e2) & with(e1,x3) & n_people(x3) & Theme(e1,x2) & Actor(e1,x1) & v_cover(e1) & n_street(x2) & n_snow(x1))
exists e1 p1 x1.(n_snow(x1) & Topic(e1,p1) & Actor(e1,x1) & v_start(e1) & exists e2 x2.(to(e2,x2) & n_ice(x2) & Actor(e2,x1) & v_turn(e2)))