A woman who had voiced complaints online about YouTube opened fire with a handgun at the tech company’s headquarters near San Francisco on Tuesday, wounding three people before shooting herself dead.

It was the latest in a string of mass shootings in the United States in recent years. Most recently, the massacre of 17 people at a Florida high school has led to calls for tighter curbs on gun ownership.

Police did not identify the suspect or say what might have motivated Tuesday’s shooting at YouTube, a video-sharing service owned by Alphabet Inc’s Google which employs nearly 2,000 people at the San Bruno, California offices.

The woman approached an outdoor patio and dining courtyard on the campus around lunchtime and began to fire before entering the building, police said.

The shooter has since been identified as Nasim Aghdam.

The 39 year old YouTube user had issues with the company and released a video last year voicing her opinion of the video streaming giant.