WASHINGTON (CNN) -- A man who set himself on fire at the National Mall has died from his injuries, police said Saturday.

Authorities haven't been able to identify him due to the extent of his injuries, so they will conduct DNA tests and use dental records, said Officer Araz Alali, spokesman for D.C. Metropolitan police.

The man was taken to a hospital Friday night after officers rushed to the scene and found the man engulfed in flames.

Alali said authorities are trying to figure why the man self-immolated.

Adam Stifel saw part of the incident while he was jogging.

"I saw a man sitting in flames," Stifel told CNN. "He had already doused himself in gasoline, I believe."

Stifel said five or six people used their shirts to pat out the fire. He said he saw a red gasoline canister near the man.

The incident occurred near the National Air and Space Museum.

The location where the man was found on fire is about six blocks from the U.S. Capitol, where a high speed car chase on Thursday ended with a woman being shot and killed by law enforcement officers.