A driver lost consciousness at a downtown intersection Friday morning, causing a minor traffic accident.

The driver of a black, late-model Honda sedan apparently lost consciousness as he was driving on Temple Street toward Congress Street.

“I saw his head fall,” said Andrew Hanson, who walked by the scene on Temple Street, a few feet away from the accident. “He was normal and then suddenly he was not.”

The Honda continued forward for several feet after the driver passed out, scraping against the side of a commercial van that was stopped and waiting to make a turn in the next lane. Hanson said the man had a dark substance coming from his mouth.

Hanson said another passerby flagged down a passing fire engine. The doors to the car were locked, so firefighters had to break a window to get to the driver, a man who appeared to be in his 20s.

Firefighters and EMTs appeared to administer a blood-sugar test to the driver, Hanson said.

The driver eventually regained consciousness and was able to get out of the vehicle and onto a stretcher with the help of EMTs. Damage to both vehicles appeared minor.