Texas Army National Guard officials say two crew members aboard an Apache helicopter on a routine training mission have died when their aircraft crashed in Galveston Bay just off the shoreline about 25 miles southeast of Houston.

Chief Warrant Officer 5 Glen Webb says names of the victims are being withheld until their relatives are notified.

The helicopter was based at nearby Ellington Field.

Witnesses said the aircraft broke apart in the air late Wednesday afternoon.

Debris and a small oil slick were on the bay. A piece of the chopper's blade was found on land near the crash site.

Divers were working into the night to retrieve the victims. The wheels of the helicopter poked above the water's surface about 25 yards from shore near a vacant cruise ship terminal.