HAUPPAUGE, N.Y. (WPIX) -- A Long Island father and his two young children were killed early this morning when their car veered off the road and struck a tree, before bursting into flames, Suffolk County Police say. The tragic accident happened around 1 a.m. in Hauppauge on the Long Island Expressway.

The victims are identified as 44-year-old Arthur Reece of Selden, his stepson, Delano Anderson, 5, and 10-month old daughter Larissa.

Investigators say a truck driver and an off-duty cop attempted to help the family, but the Jeep was already fully engulfed. Police said the trucker had a fire extinguisher, but neither he nor the officer could overcome the heat.

The children's mother was working at a local hospital when the accident occurred. Reece had just finished dropping his brother off shortly before the accident, cops say.

Police are still trying to determine what caused the Jeep to veer off the road, and it's still unclear whether the fire started before or after the vehicle made impacted the tree.

Suffolk County police are appealing to the public for help in their investigation. Anyone who may have witnessed the accident or may have information is being asked to contact the Fourth Squad at 631-854-8452.