A cyclist has been struck by a train near the North Adelaide railway station.
Witnesses called police and emergency services just after 5pm on Thursday.
The man, who had been crossing the tracks at a pedestrian crossing, was conscious and breathing when crews arrived.
He was rushed to the Royal Adelaide Hospital.
The Gawler rail line was closed for about three hours while Major Crash officers investigated the cause, with substitute buses replacing the service between Adelaide and Mawson Lakes.
The former head of trauma at the Royal Adelaide Hospital, Bill Griggs, happened to be riding his bike across the same crossing soon after the crash.
He said he helped the man until MedSTAR paramedics took over.
"It's just a very sad episode and my heart goes out to the person who was injured and to his family and friends, and also to the train driver, because these things are very distressing to train drivers," Dr Griggs said.
The Gawler rail line reopened on June 12 after being closed for 18 months for electrification.
The train that hit the cyclist was a diesel train.
