Abstract An embankment on the new Ohio Turnpike, 35 feet high, started to fail on September 1, 1955, just a month prior to the date of opening of the highway. The toe of the north side of the embankment started to bulge, and cracks developed on the flanks and in the pavement. The situation was controlled by placing backfill on the toe and flank of the embankment, making the final slope 1 to 3, with an intermediate berm of 1 to 10. Grout was placed beneath the pavement to fill the voids caused by the slumping. Boreholes drilled through the embankment indicated that cause of failure was pore pressure and instability developed in lake beds underlying the embankment. Maximum pore pressures of 13 feet were observed, which in the ensuing months gradually declined.