Owned by Lehigh Southwest Cement, the Permanente Quarry is a limestone and aggregate mining operation and cement plant in the foothills above Cupertino. It produces about 1.2 million tonnes of cement per year.
According to USA Today, the gunman Shareef Allman was attending a routine safety meeting at 4.30am, when he became upset and left. Allman returned with a handgun and automatic rifle, then opened fire on the staff.
Two people were confirmed dead on the site, while another died later in hospital: Mark Munoz, 59, John Vallejos, 51, and Manuel Pinon, 48. Some of the six injured persons remain in critical condition.
Later that morning, a man matching Allman?s description hijacked a car at Hewlett-Packard?s Cupertino campus, injuring the female driver when he shot her in the leg.
A statement from Lehigh Hanson claimed Allman stole a company radio, which he was using to monitor police activity. According to The Washington Post, Allman also used it to threaten the workers remaining in the plant that he was about to return to ?finish them off?.
In the days preceding Allman?s tragic ? though still somewhat mysterious ? breakdown, concerns were raised over the haul truck driver?s safety record.
Union official Mike Ambrosio told The San Jose Mercury that a meeting was planned with quarry management to discuss Allman?s poor driving. Ambrosio had reportedly ?read the riot act? to Allman over his safety concerns.
According to a Jose Rivas, a survivor who worked on a conveyor belt, Allman was angry over a recent suspension for a driving incident. Another said that Allman was being undermined by co-workers because of his race. Company officials denied the allegation.
And, according to the paper, Allman?s neighbour told the paper he?d been upset about a recent move to the night shift from the day shift, complaining that it interfered with his time with his daughter.
Allman, who?d recently returned from a month-long holiday, had been working at the quarry for almost 20 years, and, according to friends, was looking forward to retiring in just another three.
A co-worker, Charles Bryan, who also drives a haul truck at the quarry, told The LA Times, that Allman had been behaving very strangely that morning.
?This is really weird,? he said. ?Yesterday it was like no one else was there but him. Our work is very dangerous. We?re supposed to have eye contact with each other. But yesterday it was like we weren?t there.?
Besides working in the quarry, Allman was reportedly an active community member, running a not-for-profit youth group, Helping Hands Changing Hearts, and producing and hosting a public access television show.
?He’s always had a smile on his face,” Allman?s neighbour, Paulette Conner, 57, who has known Allman for five years, told USA Today. “I’ve never known him to have any violent tendencies. Never. Ever.”
Lehigh Hanson issued a statement about the tragic events, offering condolences to the victims.
?Our thoughts and prayers are with the victims and their families,” Dan Harrington, president and chief executive of Lehigh Hanson said in a statement. “I have committed the company’s resources to assist our affected employees during this difficult time.”