HUNTSVILLE, ALA. - Authorities say a woman opened fire Friday afternoon during a biology faculty meeting at the University of Alabama's Huntsville campus, killing three biology professors and injuring three other school employees.

WAFF, an NBC affiliate, quoted school officials as saying the professor -- a Harvard-educated neurobiologist -- began shooting after learning at the faculty meeting that she was being denied tenure.

Amy Bishop, an instructor and researcher at the university, was charged later Friday with one count of capital murder, which means she could face the death penalty if convicted.

Bishop was taken in handcuffs to the county jail and could be heard saying, "It didn't happen. There's no way ... they are still alive."

The shooting occurred in the university's Shelby Center about 4 p.m., officials said. Few students were in the building, and none was involved in the shooting, said Ray Garner, a university spokesman.

University spokesman Ray Garner said the three killed were Gopi K. Podila, the chairman of the Department of Biological Sciences, and two other faculty members, Maria Ragland Davis and Adriel Johnson.

The injured were identified as department members Luis Cruz-Vera, who was listed in fair condition and Joseph Leahy and staffer Stephanie Monticello, both of whom were in critical condition in intensive care.

Sammie Lee Davis said his wife, Maria Ragland Davis, was a researcher who had tenure at the university. He said he was told his wife was at a meeting to discuss the tenure status of another faculty member who got angry and started shooting.

He said his wife had mentioned the shooter before, describing the woman as "not being able to deal with reality."

Bishop joined the biology faculty as an assistant professor in 2003. She and her husband, Jim Anderson, placed third in a statewide university business plan competition in July 2007, presenting a portable cell incubator they had invented. They won $25,000 to help start a company to market the device.

Police officials said that Anderson was being detained, but they did not call him a suspect.

Justin Wright, a senior, was working in the building's math lab when the police burst in with guns drawn. He told the Huntsville Times that his first thoughts were, "I need to get down, I need to get down." He added: "I've never seen a gun or heavy artillery like that. I was shocked."

The shooting came just a week after a middle school student in Huntsville shot and killed a classmate, leaving the town in shock. "This is a very safe campus," Garner said. "This town is not accustomed to shootings and having multiple dead."

The university was put on lockdown "almost instantaneously," said Trent Willis, chief of staff to Mayor Tommy Battle. However, some students said on Twitter that they did not receive the university's alert until hours after the shooting.

"The U-Alert was triggered late because the people involved in activating that system were involved in responding to the shooting," said Charles Gailes, chief of the university police.

The Huntsville campus has about 7,500 students in northern Alabama, not far from the Tennessee line. The university is known for its scientific and engineering programs and often works closely with NASA.

The New York Times and Associated Press contributed to this report.