Commerce Secretary Bryson, in Hit-and-Run, Said to Suffer Seizure LOS ANGELES - It began Saturday afternoon at a railroad crossing in a run-down commercial neighborhood in suburban San Gabriel, on a street bustling with signs in Chinese characters. A man in a Lexus rolled into the back of a Buick waiting for a train to pass. Two miles and five minutes later, the Lexus smacked into the rear of yet another car, in neighboring Rosemead. The Los Angeles Sheriff's Office found the driver passed out at the wheel and took him to the hospital for observation. He was cited for a hit-and-run. The driver was John E. Bryson, the commerce secretary, one of the lower-profile members of President Obama's cabinet but a well-known figure in California energy and business circles. The episode set off a squall of speculation and questions from here to the White House about what precisely had happened in the San Gabriel Valley, as Mr. Bryson returned to work as usual Monday at his office in Washington and made no public appearances or statements as of late afternoon. The White House said that Mr. Bryson had suffered a seizure. But officials there and at the Commerce Department declined to offer details on Mr. Bryson's medical history, including what might have caused the seizure, and took pains to say they were not saying the seizure caused the accident. They said that this was the first such seizure he had suffered. "The commerce secretary was alone," said Jay Carney, the White House spokesman. He had a seizure. He was involved in an accident. White House officials said that Mr. Bryson had told them that he did not recall the events leading to the accident. Mr. Bryson passed a breathalyzer test at the scene, and submitted to a blood toxicology test, said Steve Whitmore, a spokesman for the Los Angeles County Sheriff's Office. He said that if the toxicology report came back negative, Mr. Bryson would not be charged. There were no significant injuries, or heavy vehicular damage, in either accident, which took place shortly past 5 p.m. on Saturday. Mr. Bryson, 68, maintains a home here in San Marino, not far from where the accidents occurred, and in Washington, according to friends. He was in town to deliver a commencement address at Polytechnic School, a private prep school in Pasadena that his four daughters attend. He was not accompanied by a security detail, officials said. Mr. Bryson kept a low-profile in the community - some neighbors said they were not even aware who lived in the handsome two-story house at the end of a cul-de-sac on a hill - though they had noted a police car parked there at times. A black Lexus was parked in front of his house on Monday, but there was no answer at the door. The police can arrest a driver in a hit-and-run incident, but Mr. Bryson was cited instead because he needed to go to the hospital, Mr. Whitmore said. The San Gabriel police apparently allowed him to leave the state after he was released from the hospital, he said. According to the police, Mr. Bryson's car hit the Buick, which had three men inside, at the railroad crossing. He got out to offer to exchange information, then returned to his car and slowly drove away. As he was leaving, he hit the car again, the police said. The three men followed Mr. Bryson as he drove two miles up San Gabriel Boulevard and called 911, before he hit the second car, a Honda Accord. Cesar Castaneda, 27, who works at Karina's Tacos, on the corner of where the second accident occurred, said the Lexus did not appear to have been damaged. "I saw them as towing was taking the Lexus away," he said. The Commerce Department notified the White House of the incident on Sunday evening, and Mr. Obama was informed Monday morning. The president had not spoken with Mr. Bryson as of 2 p.m. Monday. Many of Mr. Obama's nominations have been hit with a fusillade of complaints from the right and the left, but Mr. Bryson's appointment as commerce secretary last May, to succeed Gary F. Locke, who had been named ambassador to China, at first drew plaudits from both business and environmental groups, testimony to his career in both worlds. But it soon became ensnared. Mr. Bryson, the former chief executive of Southern California electric conglomerate Edison International and the founder of the Natural Resources Defense Council, an environmental group, was accused by Senator James Inhofe, Republican of Oklahoma, of advocating Mr. Obama's "job-killing" environmental agenda. Mr. Bryson was confirmed five months later, in October 2011. On Monday, shortly after news of Mr. Bryson's accident became known, American Crossroads, the "Super PAC" run by Karl Rove, the Republican strategist, posted on Twitter asking how Mr. Bryson could have had three car crashes in five minutes "and alcohol NOT be involved." As more details about the accident emerged, Crossroads apologized for the post. Mr. Bryson has a valid driver's license issued in California. Dr. Keith L. Black, the chairman of the neurosurgery department at Cedars-Sinai Medical Center, said that the Department of Motor Vehicles would typically respond to this kind of episode by suspending the motorist's driver's license for six months, pending a review of the person's medical treatment. Mr. Bryson helped to found the Natural Resources Defense Council in 1970, and spent almost 20 years at Southern California Edison. He also served as president of the California Public Utilities Commission. "He's a pillar of the community type," said Geoffrey Cowan, a longtime friend who is the president of the Annenberg Foundation Trust at Sunnylands. Adam Nagourney reported from Los Angeles and Helene Cooper from Washington. Jennifer Medina contributed reporting from Los Angeles, Ian Lovett from San Gabriel, Calif., Ana Facio-Krajcer from San Marino, Calif.; and Michael D. Shear from Washington.