A fire ripped through the oceanfront Sandpiper co-op apartments on Dune Road shortly after 3 p.m, reports riverheadlocal.com.
Riverhead was one of many area fire departments called by Westhampton Beach to help battle the fire, which reportedly burned through 40 of the 60 units at the complex. Riverhead vols responded with a ladder truck to the scene.
Billowing black smoke from the fire could be seen for miles and was visible from the North Fork.
Riverhead Volunteer Ambulance Corps was called to the scene to stand by at 5:25 p.m.