It happened Saturday around 12:30 p.m. at the building on 54th Street in Woodside.
Police originally reported a 69-year-old woman and a 57-year-old man were stabbed - then later said a 35-year-old man and a 46-year-old woman were also stabbed.
Police took the suspect into custody at the scene.
Neighbors say the man is emotionally disturbed.
All four victims are expected to survive.
ALSO READ | Man accused of squatting in Queens home faces judge, promises 'revelation' in case
Queens squatter faces judge and promises 'revelation' in case
----------
* More Queens news
* Send us a news tip
* Download the abc7NY app for breaking news alerts
* Follow us on YouTube
Submit a tip or story idea to Eyewitness News
Have a breaking news tip or an idea for a story we should cover? Send it to Eyewitness News using the form below. If attaching a video or photo, terms of use apply.