FLATLANDS - Neighbors were in mourning Monday as investigators tried to determine the cause of a fiery crash that killed a Flatlands family of five, including three children, on the Southern State Parkway on Long Island.

Police say 37-year-old Myriam Lebrun was behind the wheel of a Honda Accord when it veered off the road, struck a tree and burst into flames Saturday night in Babylon. Lebrun's 68-year-old mother, Yolande Moise, and her children, 14-year-old Marquis Jeanty, 9-year-old Marcel Jeanty and 8-year-old Kayla Jeanty were also killed in the crash.

"Me and my husband, we can't even sleep. We loved them so much," says Janine Serapsin, the family's landlord. "We are going to miss them a lot. They have been living here for five years, but they are more like family to us." 

The victims' neighbors have set up a makeshift memorial with candles and stuffed animals outside their East 55th Street home. 

Charles Knapp of the state police says investigators are working to determine whether speed and alcohol were factors in the wreck.

AP contributed to this story.