HARTFORD, Conn. (AP) — A business jet flying over New England violently pitched upward then downward, fatally injuring a passenger, after pilots responding to automated cockpit warnings switched off a system that helps keep the aircraft stable, U.S. transportation investigators reported Friday.

The National Transportation Safety Board didn’t reach any conclusions in its preliminary report on the main cause of the deadly March 3 accident, but it described a series of things that went wrong before and after the plane swooped out of control.

Confronted with several alerts in the cockpit of the Bombardier jet, pilots followed a checklist and turned off a switch that “trims” or adjusts the stabilizer on the plane’s tail, the report said.

The plane’s nose then swept upward, subjecting the people inside to forces about four times the force of gravity, then pointed lower before again turning upward before pilots could regain control, the report said.

Pilots told investigators they did not encounter turbulence, as the NTSB had said in an initial assessment the day after the incident.

The trim system of the Bombardier Challenger 300 twin-engine jet was the subject of a Federal Aviation Administration mandate last year that pilots conduct extra safety checks before flights.

Bombardier did not respond directly to the report’s contents, saying in a statement that it was “carefully studying” it. In a previous statement, the Canadian manufacturer said it stood behind its Challenger 300 jets and their airworthiness.

“We will continue to fully support and provide assistance to all authorities as needed,” the company said Friday.

The two pilots and three passengers were traveling from Keene, New Hampshire, to Leesburg, Virginia, before diverting to Bradley International Airport in Connecticut. One passenger, Dana Hyde, 55, of Cabin John, Maryland, was brought to a hospital where she died from blunt-force injuries.

Hyde served in government positions during the Clinton and Obama administrations and was counsel for the 9/11 Commission, formally known as the National Commission on Terrorist Attacks Upon the United States.

It was unclear if Hyde was belted in her seat or up and about, in the cabin of the jet owned by Conexon, based in Kansas City, Missouri. Her husband and their son, along with the pilot and co-pilot, were not injured in the incident, the report said.

A representative of Conexon, a company specializing in rural internet, declined to comment Friday.

The report indicated the pilots aborted their initial takeoff because no one removed a plastic cover from one of the exterior tubes that determine airspeed, and they took off with a rudder limiter fault alert on.

Another warning indicated autopilot stabilizer trim failure. The plane abruptly pitched upward as the pilots moved the stabilizer trim switch from primary to off while working through procedures on a checklist, the report said.

The plane violently oscillated up and down and the “stick pusher” activated, the report said, meaning the onboard computer thought the plane was in danger of an aerodynamic stall.

John Cox, a former airline pilot and now a safety consultant, said “there are definitely issues” with the pilots’ pre-flight actions, but he said they reacted correctly when they followed the checklist for responding to trim failure.

The flight crew was comprised of two experienced pilots with 5,000 and 8,000 hours of flying time, and held ratings needed to fly for an airline. But both were relatively new to the model of aircraft, earning their ratings last October.

The FAA issued its directive about Bombardier Challenger 300 jets last year after multiple instances in which the horizontal stabilizer on the aircrafts caused the nose of the plane to turn down after the pilot tried to make the aircraft climb.

Related: 1 killed when business jet encounters severe turbulence

WEST READING, Pa. (AP) — An explosion at a chocolate factory in Pennsylvania on Friday killed five people and left six people missing, authorities said.

The Pennsylvania Emergency Management Agency confirmed the increase in the number of fatalities Saturday morning after the blast just before 5 p.m. Friday at the R.M. Palmer Co. plant in the borough of West Reading.

Chief of Police Wayne Holben said the blast destroyed one building and damaged a neighboring building.

“It’s pretty leveled,” Mayor Samantha Kaag said of the explosion site. “The building in the front, with the church and the apartments, the explosion was so big that it moved that building four feet forward.”

The cause of the blast in the community about 60 miles (96 kilometers) northwest of Philadelphia was under investigation, Holden told reporters. Authorities are investigating the possibility that a gas leak may have been responsible, a spokesperson for the Pennsylvania Emergency Management Agency said.

Eight people were taken to Reading Hospital Friday evening, Tower Health spokeswoman Jessica Bezler said.

Two people were admitted in fair condition and five were being treated and would be released, she said in an email. One patient was transferred to another facility, but Bezler provided no further details.

Kaag said people were asked to move back about a block in each direction from the site of the explosion but no evacuations were ordered.

Dean Murray, the borough manager of West Reading Borough, said some residents were displaced from the damaged apartment building.

Kagg said borough officials were not in immediate contact with officials from R.M. Palmer, which Murray described as “a staple of the borough.”

The company’s website says it has been making “chocolate novelties” since 1948 and now has 850 employees at its West Reading headquarters.

SAN FRANCISCO (AP) — Gordon Moore, the Intel Corp. co-founder who set the breakneck pace of progress in the digital age with a simple 1965 prediction of how quickly engineers would boost the capacity of computer chips, has died. He was 94.

Moore died Friday at his home in Hawaii, according to Intel and the Gordon and Betty Moore Foundation.

Moore, who held a Ph.D. in chemistry and physics, made his famous observation — now known as “Moore’s Law” — three years before he helped start Intel in 1968. It appeared among a number of articles about the future written for the now-defunct Electronics magazine by experts in various fields.

The prediction, which Moore said he plotted out on graph paper based on what had been happening with chips at the time, said the capacity and complexity of integrated circuits would double every year.

Strictly speaking, Moore’s observation referred to the doubling of transistors on a semiconductor. But over the years, it has been applied to hard drives, computer monitors and other electronic devices, holding that roughly every 18 months a new generation of products makes their predecessors obsolete.

It became a standard for the tech industry’s progress and innovation.

“It’s the human spirit. It’s what made Silicon Valley,” Carver Mead, a retired California Institute of Technology computer scientist who coined the term “Moore’s Law” in the early 1970s, said in 2005. “It’s the real thing.”

Moore later became known for his philanthropy when he and his wife established the Gordon and Betty Moore Foundation, which focuses on environmental conservation, science, patient care and projects in the San Francisco Bay area. It has donated more than $5.1 billion to charitable causes since its founding in 2000.

“Those of us who have met and worked with Gordon will forever be inspired by his wisdom, humility and generosity,” foundation president Harvey Fineberg said in a statement.

Intel Chairman Frank Yeary called Moore a brilliant scientist and a leading American entrepreneur.

“It is impossible to imagine the world we live in today, with computing so essential to our lives, without the contributions of Gordon Moore,” he said.

In his book “Moore’s Law: The Life of Gordon Moore, Silicon Valley’s Quiet Revolutionary,” author David Brock called him “the most important thinker and doer in the story of silicon electronics.”

Moore was born in San Francisco on Jan. 3, 1929, and grew up in the tiny nearby coastal town of Pescadero. As a boy, he took a liking to chemistry sets. He attended San Jose State University, then transferred to the University of California, Berkeley, where he graduated with a degree in chemistry.

After getting his Ph.D. from the California Institute of Technology in 1954, he worked briefly as a researcher at Johns Hopkins University.

His entry into microchips began when he went to work for William Shockley, who in 1956 shared the Nobel Prize for physics for his work inventing the transistor. Less than two years later, Moore and seven colleagues left Shockley Semiconductor Laboratory after growing tired of its namesake’s management practices.

The defection by the “traitorous eight,” as the group came to be called, planted the seeds for Silicon Valley’s renegade culture, in which engineers who disagreed with their colleagues didn’t hesitate to become competitors.

The Shockley defectors in 1957 created Fairchild Semiconductor, which became one of the first companies to manufacture the integrated circuit, a refinement of the transistor.

Fairchild supplied the chips that went into the first computers that astronauts used aboard spacecraft.

In 1968, Moore and Robert Noyce, one of the eight engineers who left Shockley, again struck out on their own. With $500,000 of their own money and the backing of venture capitalist Arthur Rock, they founded Intel, a name based on joining the words “integrated” and “electronics.”

Moore became Intel’s chief executive in 1975. His tenure as CEO ended in 1987, thought he remained chairman for another 10 years. He was chairman emeritus from 1997 to 2006.

He received the National Medal of Technology from President George H.W. Bush in 1990 and the Presidential Medal of Freedom from President George W. Bush in 2002.

Despite his wealth and acclaim, Moore remained known for his modesty. In 2005, he referred to Moore’s Law as “a lucky guess that got a lot more publicity than it deserved.”

He is survived by his wife of 50 years, Betty, sons Kenneth and Steven, and four grandchildren.