PHILADELPHIA (CBS) — A driver was seriously injured overnight when his vehicle rearended a tow truck in South Philadelphia.

It happened around 2 a.m. Monday near the intersection of Penrose and Pattison Avenues.

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Police say the driver, an unidentified man, slammed his vehicle into a two truck from behind.

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He was taken to Presbyterian Hospital with unstable vital signs.

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Police are investigating the cause of the crash.