The New York Blood Center, which provides blood, transfusion products and services to hospitals in parts of Connecticut, says it has less than a two-day supply of O-negative "universal donor'' blood heading into the Labor Day weekend. 

The center said Thursday it tries to maintain a seven to nine-day supply of all blood types.  O-negative can be transfused into anyone during a trauma situation when there's no time for blood typing. 

There are blood drives Thursday at Danbury Hospital and Friday at Walnut Hill Community Church in Bethel.