Navy Cross medals were presented yesterday to the families of two Marines who were killed while thwarting a suicide bomber and saving the lives of dozens of Marines and Iraqis.

Lance Cpl. Jordan Haerter, 19, and Cpl. Jonathan Yale, 21, died April 22, 2008, while standing guard outside a Marine and Iraqi police compound in Ramadi, Iraq. They were the only ones to continue firing at a truck laden with 2,000 pounds of explosives that was racing toward the gate they were guarding.

The truck exploded, fatally injuring the Marines and flattening nearby buildings. But at least 50 Marines and Iraqi police in the compound were spared.

FOURTH DELAY FOR SHUTTLE LAUNCH

CAPE CANAVERAL, Fla. — NASA has delayed the launch of space shuttle Discovery for a fourth time amid valve concerns.

After meeting all yesterday at Kennedy Space Center in Florida, shuttle managers decided against launching in a week. The launch had been targeted for no sooner than Feb. 27; it was not immediately known late yesterday when it might be rescheduled.

NASA originally hoped to send Discovery to the international space station on Feb. 12. But extra tests were ordered for the valves that control the flow of hydrogen gas into the external fuel tank during liftoff. One of those valves broke during the last shuttle launch in November.

TAMIL TIGERS' AIR ATTACK KILLS 4

COLOMBO, Sri Lanka — Tamil Tiger rebels said today the two planes they sent on a daring air attack over Sri Lanka's capital that killed four people and injured 51 were on a kamikaze mission and were not shot down.

Authorities pulled the wreckage of one plane out of a government high-rise office building near air force headquarters in the middle of the city. The second plane crashed near an air force base just outside the international airport north of Colombo.

3 TROOPS DEAD IN AFGHAN BOMBING

KABUL, Afghanistan — A roadside bomb killed three coalition troops yesterday during a patrol in Afghanistan's dangerous south, the U.S. coalition said.

The attack came in Uruzgan province. The coalition did not release any other information, including the troops' nationalities. U.S., Dutch and Australian troops operate in Uruzgan.