Houston police said that in an ordeal that lasted almost four hours, a white male who had barricaded himself with a weapon inside Building 44 at NASA's Johnson Space Center in Houston, had killed himself and one male hostage. The male hostage was shot in the chest.

A female hostage who was also discovered duct taped at the scene is receiving medical attention; but is believed to be all right.

ABC News local affiliate KTRK reported that the suspect was 60-year old William Phillips Jr.

In a press conference, Houston Police Capt. Dwayne Ready said that police heard a gunshot and decided to break through the barricade. They discovered that the suspect had shot himself in the head. Ready also said the suspect was carrying a sort of revolver or handgun with a 2-inch barrel.

Ready had earlier confirmed that two shots were fired in Building 44, which led to police responding to the situation. He said that the deceased hostage was likely killed by one of these initial gunshots.

He said that a little before 1 p.m. local time police were alerted to the situation at the Johnson Space Center, and they made a call to a SWAT team. He said that law enforcement officials had tried to establish communication with the suspect but added, "we never did establish communication."

He did not confirm that the suspect or the hostages were employees of NASA. Ready added that the suspect was on the second floor of Building 44.

Johnson Space Center's spokeswoman Eileen Hawley said NASA employees were informed of the situation via e-mail.

Building 44 is one block west of Mission Control.