EL CAJON, Calif. — An East County freeway on-ramp was closed Tuesday due to a semi-truck overturning and spilling a trailer full of manure onto the road, California Highway Patrol officials confirmed.

The crash happened around 7 a.m. on the Interstate 8 off-ramp at Magnolia Avenue in El Cajon when the big rig tipped over, spilling manure onto the roadway, according to CHP logs.

A Sig-Alert was issued and the eastbound I-8 off-ramp at Magnolia Avenue and southbound Magnolia Avenue on-ramp to eastbound I-8 were closed due to the spill, Caltrans San Diego said in a tweet.

Crews are working to clean the roadway and it is not yet known how long the closure will be in place. As of 9:30 a.m. CHP logs showed the Sig-Alert was still in place.

The semi-truck was the only vehicle involved in the incident, according to CHP.