MESA, AZ (3TV/CBS 5) -- A wrong-way driver slammed into another car in Mesa on Saturday afternoon, the Mesa Police Department reported.
A man who watched the whole thing unfold caught the accident on camera.
"Since he was driving kind of erratically, I decided to take the video," said Greg Heinrich.
The video shows the driver crashing into another car at a red light near Southern and Stewart avenues.
According to Mesa Police, the wrong-way driver was an elderly person who became confused. Heinrich added that the driver looked lost.
"He was halfway on the curb," said Heinrich about the wrong-way driver. "He just looked confused. Something just registered [that] something's not right with this guy."
Heinrich said the wrong-way driver ran the red light and made contact with the vehicle like a magnet.
[WATCH: Raw video of Mesa wrong-way crash]
Heinrich's passenger called 911 right after the crash occurred.
The wrong-way driver was sweating a lot and not responding when questioned by officers, according to Heinrich.
Police say no one was seriously injured during the accident.
"I'm just grateful no one else was hurt because at the beginning of the video he almost hit somebody else," said Heinrich. "And it just makes me think how important it is to pay attention when you are driving."