A Taiwanese divorcee rammed the Presidential Office in Taipei with a 35-tonne truck yesterday, in the most serious security breach of its type on the island. The driver, identified as Chang Te-cheng, powered the gravel truck up a flight of steps, past security posts, through four types of security barrier, including iron railings, tyre shredders and a huge bulletproof screen, and into the foyer of the building. It came to rest 20 metres below the third-floor office of President Ma Ying-jeou, who was visiting Sao Tome and Principe, a former Portuguese colony in Africa, at the time. The incident happened at around 5am, police said. The barriers reduced the impact of the crash, with only a small part of the driver's cabin wedged in the main gate, which showed little other damage. Chang, 41, who was knocked unconscious, was admitted to hospital with a number of injuries, none of which were life-threatening, doctors said. His condition was stable. He refused to answer questions from police when he regained consciousness, but had left a note at home asking his mother to take good care of herself and that his two children not learn from him, police said. It was the third vehicular incident on the terrace of the Presidential Office during Ma's tenure, and the 13th since 2003. However, the earlier events were all regular traffic accidents or cases of drink-driving. Police and security experts ruled out a political motive for the attack, which they said was more to do with Chang's frustration with an unhappy life. "The attack was intentional and planned well ahead, but it had nothing to do with politics, but rather personal unhappiness and frustration," said Fang Yang-ning of the Taipei police at a press conference. Chang was twice divorced and had a history of domestic violence against his second wife. Preliminary investigations showed he had planned the attack apparently to air his discontent with his life, police said. He was found to have visited the Presidential Office when it was open to the public and had written on his Facebook page that he would do something to make himself known. The incident prompted lawmakers from both sides of the political divide to question the adequacy of security measures around the Presidential Office. Ma ordered a thorough investigation. Some opposition lawmakers have criticised the Ma government for failing to improve the island's economy, causing some people to lose hope.