Update 12:05: CHP is reporting that lanes will be closed for at least a few more hours.
The California Highway Patrol is reporting that a fatal collision on Highway 99 is backing up northbound traffic Tuesday morning.
The collision was reported at 9:32 a.m. Tuesday after a big rig went over the embankment, while another vehicle overturned.
At least one fatality has been reported by CHP.
All lanes of northbound Highway 99 were closed for some time due to a nail spill, but the No. 1 lane has been opened as of 10:15 a.m. The lane closures caused traffic to be backed up into Merced.
It is unknown when the other two lanes will open.
Turlock police have also responded to assist CHP by closing Main Street under Highway 99 as a precautionary measure if the big rig rolls down the embankment.
TurlockCityNews.com will release more details once they are available.