A man was killed after being struck by a train this morning, stalling traffic in downtown Tucson, authorities said.

All railroad crossing are shut down from North Main Avenue to North Seventh Avenue, said Capt. Andy Skaggs, a Tucson Fire Department spokesman.

TFD is advising motorists to avoid the downtown area, specifically railroad tracks, for the next several hours.

Jeff DeGraff, a Union Pacific spokesman, told the Associated Press that the freight train's crew applied the brakes but didn't have time to stop before their train struck and killed the man.

The man emerged from bushes and walked onto the tracks as the westbound 51-car train was passing through downtown Tucson, he said.

The incident occurred near West Sixth Street and North Ninth Avenue.

Contact reporter Caitlin Schmidt at cschmidt@tucson.com or 573-4191