The man injured at the Crystal City Metro station late Thursday night was sitting on the station platform with his legs dangling over the edge even as a train approached the station, police said yesterday.

As the white platform lights started blinking, warning of an oncoming train, a bystander yelled for Nelson Alfaro to get up and out of the way. But Alfaro did not budge and was hit by the train as its operator attempted to stop.

The 23-year-old Rockville man was in good condition yesterday at Washington Hospital Center after undergoing several hours of surgery on his left leg during the afternoon, said hospital spokesman LeRoy Tillman.

Metro transit police said the incident remained under investigation yesterday. Detectives planned to interview two people who had been standing on the platform and saw what happened.

Alfaro, a Salvadoran immigrant, lives in a small brick house in Rockville with a cousin and his family. Marta Carballo, a relative who was at the house yesterday, said she thought Alfaro was on his way back from a Northern Virginia restaurant where he is a cook.

"We are still waiting to find out what happened," she said yesterday. "We were all very surprised by this. It's not something you would ever expect."

Carballo said that Alfaro's wife and children are in El Salvador and that she was surprised at police accounts that he was sitting on the platform when the accident occurred.

The four-car train came into the station about 9:59 Thursday night. It was carrying three police officers and two revenue technicians who were transporting money from fare card machines to a Metro facility in New Carrollton.

The train was not taking passengers and was not scheduled to stop in Crystal City.

When the train reached the station, the operator spotted Alfaro and pulled the emergency brake and held the horn, said Sgt. Amy Phillips of the transit police. The train did not stop until two cars had passed against Alfaro's legs.

"His legs were wedged between the train and the platform," said Polly Hanson, deputy chief with the Metro transit police.

Alfaro's left leg was broken and his right leg was swollen once rescue workers had pried him from between the train and the platform, Hanson said.

Metro police said they did not know how fast the train was moving. Metro regulations call for trains to travel no faster than 25 mph through stations when they do not plan to stop, said agency spokeswoman Cheryl Johnson.

A police officer and technician got off the train and administered first aid, Hanson said. Some 20 Arlington rescue workers arrived and used two inflatable bags to push the train away from the platform edge and free Alfaro.

Alfaro told one of the Metro workers that he had been drinking earlier in the evening, Hanson said.

Carballo said she was skeptical of this account because Alfaro did not drink alcohol on nights when he had to work the next day. She said he was scheduled to work yesterday. Carballo said the family had not had a chance to speak with Alfaro.