The Sig Alert has been lifted on Highway 78 and traffic is moving normally.
SR-78 was shut down in both directions for several hours following a head-on two-vehicle crash Sunday evening, San Diego police confirm.
The collision happened around 5:41 p.m. at Ysabel Creek Road and San Pasqual Valley Road.
Deborah Wenberg witnessed the crash.
"It's a pretty dangerous curve. You have to watch out," she told NBC 7. "There are a lot of accidents along there."
Emergency crews were able to extricate one victim from their car and are working on extricating a second victim from the other car.
A total of four people have been taken to the hospital with unknown injuries.
The highway was closed from Bandy Canyon to San Pasqual Valley Road.
Officials do not have a cause yet.
No other information was available.
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