LEMON GROVE, Calif. - A driver and a passenger were seriously injured in a rollover crash in Lemon Grove early Monday, authorities said.

The crash at Federal Boulevard and San Miguel Avenue occurred around 2 a.m., according to San Diego County sheriff's Sgt. Luis Chavez.

A 2001 Ford sedan rolled over and landed on its roof, the sergeant said in a statement. No other vehicles were involved.

The driver of the sedan was able get out without help but firefighters cut the vehicle open to free the passenger, who was unconscious, Chavez said, adding that both victims were taken to Scripps Mercy Hospital with serious
injuries.

Federal Boulevard near San Miguel Avenue was shut down in both directions because of the wreck. Authorities were still blocking the area as of 6:30 a.m.

The cause of the crash was under investigation.