More than 4,000 members of the Faculty of Arts and Sciences (FAS) lost their jobs Tuesday morning.

All members of the Faculty and FAS administrators received an e-mail saying they no longer worked for Harvard and their e-mail accounts would be terminated in October.

Soon after, faculty members received a second e-mail reassuring them that both their jobs and their e-mail accounts were safe.

“Virtually everyone in University Hall seemed to have been terminated without notice, which seemed implausible if perhaps devoutly desired in some quarters!” Dean of the College Harry R. Lewis ’68 wrote in an e-mail.

The mistaken firings were, in fact, simply the result of Monday’s change to a new payroll system.

The FAS e-mail system, run by the Harvard Arts and Sciences Computer Services (HASCS), was not updated to reflect the change in payroll software.

An automated program sent the e-mails under the assumption that the employees whose status in the payroll system had been changed were no longer affiliated with Harvard.

FAS spokesperson Robert Mitchell said he was very confused when he received the e-mail Tuesday morning.

“At first I wasn’t sure what it meant,” he said. “I’ve only been here for three weeks. I initially thought that when I registered, the paperwork hadn’t gone through.

“Almost immediately I got a second e-mail saying it was a mistake, and there was no cause for alarm,” Mitchell said.

Kevin S. Davis ’98, coordinator of residential computing said that HASCS immediately responded to the glitch in the system.

“We want the campus to know that we’re fixing everything,” said Davis, a Crimson editor. “This really shouldn’t reflect on the new systems.”

Davis said human error at HASCS was to blame for the problem Tuesday morning.

“The old program [that sent the e-mail] should have been disabled, but it wasn’t,” Davis said.

Despite the confusion, Davis said that the FAS e-mail acounts were never in danger.