A seemingly deranged gunman carrying a can of gasoline,a propane tank and numerous rounds of ammunition opened fire into a crowd ofstudents at a Carlsbad elementary school today, grazing two second-gradersbefore being chased down and subdued by witnesses.

Brendan L. O'Rourke, 41, of Oceanside, walked onto the grounds of KellyElementary School and began shooting with a .357 Magnum revolver shortly afternoon, police said.

O'Rourke's pistol apparently ran out of ammunition before threeconstruction workers who happened to be in the area gave chase on foot and in apickup truck, police said.

One of them, Carlos Partida of Chula Vista, used the vehicle to knockdown the attacker, allowing the other two good Samaritans to catch him and holdhim for police, who arrived momentarily.

Two female students, ages 6 and 7, were admitted to Rady Children'sHospital ``with through-and-through wounds to each of the their right arms,''Carlsbad police Lt. Kelly Cain said tonight.

The campus was placed on lockdown as police worked to ensure that noother threats remained, a process that took several hours.

Sheriff's bomb-squad personnel investigated the two gas canistersO'Rourke had been carrying and ``rendered them safe,'' Carlsbad police ChiefGary Morrison said.

Though Morrison referred to the containers as ``suspicious devices,'' itwas unclear if O'Rourke had planned to ignite or detonate the fuel.

O'Rourke had left the propane tank outside his car, which was parkednear the school, police said. He apparently dropped the small gas can on oradjacent to the campus grounds.

Parents were told meet at Laguna Riviera Park, just south of the KellyDrive school, to pick up their children once an all-clear was issued. Allpupils had been reunited with family members by shortly before 4 p.m.,according to Kristina Ray, Carlsbad's communications manager.

Terry Lynn, who lives on a hill next to the campus, was in his upstairsbedroom when the gunfire rang out. He described looking out a window in horrorand disbelief.

``I saw a guy walking across the field with a handgun, shooting randomlyinto the crowd of children,'' he told NBC 7/39. ``I immediately screamed,`No, no!'''

Lynn, who said he did not see any children ``drop,'' ran outside, gotinto his van and sped the short distance to the school. As he pulled into aparking lot, he saw the construction workers go after the shooter, who fledwhen he saw them coming.

Lynn then drove to the other side of the campus, toward where the gunmanand his pursuers had run.

``By then, they had chased him over the fence and were trying toapprehend him,'' Lynn said. ``I pulled up and assisted them. They had him downon the ground. It was very chaotic. He had a .357 handgun.''

The gunman's pockets were ``full of'' extra cartridges, along with aflashlight and other ``electronic devices,'' Lynn said.

``The guy came to do destruction,'' he said. ``We were lucky.''

Lynn said the assailant seemed ``crazy.''

Initial reports that O'Rourke was wearing a Halloween outfit andcarrying a jack-o'-lantern were determined to be false, Carlsbad police saidtonight.

``It was also relayed that he had been yelling obscenities about thepresident of the United States and this was also false,'' the police statementsaid.

Officers took O'Rourke to Scripps Memorial Hospital La Jolla for anevaluation.

No motive for the shooting had been determined by late afternoon, Ray said.

Trauma counselors and police and fire department chaplains went to thescene to help those traumatized by the attack.

Carlsbad Mayor Claude ``Bud'' Lewis offered ``deep sympathy to all thechildren and families affected by today's shooting.''

Lewis said the Carlsbad Unified School District ``handled the situationwith the utmost sensitivity to its students and parents.''

``I would also like to commend our local citizens for their heroicefforts to stop the shooter,'' Lewis said. ``I am proud of the quick andthorough response of Carlsbad safety personnel and all of the other agencies(that) assisted throughout the incident.''

O'Rourke was arrested on suspicion of six counts of attempted murder andnumerous weapons violations, Carlsbad police said.