SAN FRANCISCO -- CHP units have cleared an injury accident on southbound I-280 north of the Cesar Chavez exit in San Francisco that closed lanes for almost an hour, according to authorities.

At around 2:24 p.m., CHP issued a severe traffic alert due to a crash involving with injuries and an overturned vehicle on southbound I-280 north of Cesar Chavez Street. 

Initially all southbound lanes were blocked, but within a few minutes, traffic began to move in the far right lane. As of about 3 p.m., the center lane reopened. The left lane remains blocked. 

Around 15 minutes later, all lanes were reopened.