UPDATE as of 3:45 p.m.: All lanes are cleared, but a four-mile backup remains, according to the state Department of Transportation.
INITIAL POST: A crash that happened at 12:45 p.m. just north of Bridgeport Way on southbound Interstate 5 is causing mile-long backups on both southbound I-5 and state Route 512, according to the state Department of Transportation.
The two right lanes of southbound I-5 are blocked.
State Patrol troopers are at the scene.
Check back for updates.