Two police cars responded to an emergency call around noon today when a man didn't move after tipping over his chair in front of Café Rosso near the Humanities building.

The unidentified man was sitting down near the cafe engaged in a telephone conversation and drinking coffee when he suddenly tipped over with his chair, according to a witness.

"He was sitting, speaking to his banker on the phone. Next thing you know, he's falling over," said Janna Denig, 41, a grad student who was doing homework near the scene of the accident. "He didn't move for 15 seconds and his face was bright red."

The doctor on the scene did not comment on his condition.

According to Denig, the man fell over with his chair, though his head did not hit the pavement. Several of the café's customers rushed to help the unresponsive man.

"I heard a loud thump," said junior Vannessa Roth, 21. "He wasn't moving. My first assumption was that he was having a heart attack."

A bystander assisted the man, sitting him upright in his chair, while another woman called the police Denig said.

"He seemed to be doing fine, he told us he has an appointment with his cardiologist later on today," said Denig.

The man told bystanders that he felt dizzy and was short of breath. Shortly afterwards, his face turned bright red again and he became motionless.

Shortly afterwards, the San Francisco Police Department and a doctor from the SF State Student Health Services Center arrived on the scene, and the man was taken to a local hospital.

SFPD would not comment on the incident.