Crazy Christian Falero, 23, allegedly stripped down and knocked on several doors in his Manhattan apartment building, hacking slashing anyone who answered.
Pensioners Ignacio Reyes-Collazo, 81 and Yigao Chen, 66, both died during the rampage while a further while three women, ages 60 to 85, were stabbed and a 22-year-old home attendant was punched, police said.
Survivors said he was terrified by the earthquakes.
Edwin Rivera , whose mom Isabel survived eight stab wounds told the NY Daily News: "He was screaming: 'It's the end of the world!' He was under the influence of the earthquake. That's why he did what he did."
Other neighbors said Falero has a history of mental problems in the family, also set fire to one apartment as he roamed the hallways, banging on apartment doors.
"This guy looked like a serial killer," said a construction worker who saw the suspect bolt the building, holding a butcher's knife.All the remaining victims taken to area hospitals; one was in critical condition while the other three were stable.
Residents said afterward that the suspect was seen running down the street yelling that it was the end of the world. He underwent a psychiatric evaluation at Harlem Hospital, police said.
His fifth-floor neighbor, 41-year-old Ramon Acosta, says he's known Falero for 10 years and he always seemed likable.
"I guess he just flipped," he said.