Boston Bombing Suspect Killed in Shootout [VIDEO & PHOTO]

confrontation with police and a manhunt was on for the second suspect—both of whom were believed to be involved in the fatal shooting of an MIT campus police officer during a chaotic series of events Thursday night.

Authorities said the bombing suspect who had been shown wearing a black baseball cap in photographs released Thursday was killed when confronted by police in Watertown, Mass. The second suspect, a light-skinned man with long curly hair and wearing a hoodie who police said was the bombing suspect identified wearing a white hat, was still at large Friday morning. Neither man was identified. Police warned residents that the at-large suspect was armed and dangerous.

Authorities said the injured suspect was taken to Beth Israel Deaconess Medical Center in Boston. Dr. Richard Wolfe, the hospital’s chief of emergency medicine, said the man had multiple injuries from what appeared to be both an explosive device and gunshot wounds.

Federal investigators have identities that they believe to be the two suspects and are working to verify their backgrounds.

“We believe this to be a terrorist,” said Boston Police Chief Ed Davis. “We believe this to be a man who’s come here to kill people. We need to get him in custody.”

The manhunt brought much of the Boston area to a halt on Friday. Gov. Deval Patrick ordered the city’s subway and bus system to be shut down. Authorities told commuters to stay home and stay indoors. As police conducted a sprawling search for the suspect in the Boston suburb of Watertown, authorities prohibited street traffic, told businesses there and in other surrounding areas to remain closed, and asked residents to remain inside.

The websites of the Massachusetts Institute of Technology, Harvard, Boston University and Boston College said classes were canceled Friday.

“We do not want people congregating or waiting,” said Kurt Schwartz, the Massachusetts director of emergency management. The situation, said State Police Col. Timothy Alben, “is grave.”

The Boston Marathon bombing suspect in the black hat has been killed during ashootout with police, while the suspect in the white hat is at large. (FBI/Reuters)

The violence began around 10:30 p.m., with the robbery of a 7-11 in nearby Cambridge, authorities said. The two men then fatally shot an MIT campus police officer and carjacked a Mercedes sport-utility vehicle at gunpoint, keeping the vehicle’s owner hostage for about a half-hour, police said. The owner was released at a gas station in Cambridge, authorities said. He wasn’t injured.

As police pursued the vehicle, explosive devices were thrown from the car, authorities said. “There was an exchange of gunfire” between police and the suspects,” Mr. Alben said.

A Massachusetts Bay Transportation Authority officer was wounded during the exchange.

“Our immediate concern is for those people in that neighborhood up there,” Mr. Alben said.

The marathon bombings on Monday killed three people and injured more than 170. Authorities said on Thursday that they were searching for two men and released video and photographs of them. On Thursday night, federal authorities released a new photograph of the white-capped suspect, wearing a gray-hooded sweatshirt, from a 7-11 in Cambridge.

Hundreds of police officers descended on the Cambridge and Watertown areas as the violence unfolded Thursday night, authorities said. Residents said they heard loud explosions and gunfire.

Katie Blouin, 24 years old, of Watertown, said Federal Bureau of Investigation agents and local police entered her house, searching before telling her boyfriend to lock the house’s doors.

“I’m shaking,” she said. “It just makes you so nervous.”

One of the suspects wanted for questioning in relation to the April 15 Boston Marathon bombing is seen in this handout photo released by the Boston Police Department.

Adonis Karageorgis, a 35-year-old dental student who lives in Watertown, said he heard a loud explosion from his apartment balcony

“I looked up and saw the sky light up,” he said. “You could smell the smoke.”

The MIT campus police officer wasn’t identified. The officer had multiple gunshot wounds and was taken to a nearby hospital, where he was pronounced dead, according to a statement on the Middlesex County District Attorney’s website.

Shortly before midnight Thursday, police were gathered in Watertown, and a stretch of the campus near Vassar Street and Main Street in Cambridge was cordoned off. Police were searching through woods with dogs and flashlights.

Dozens of police officers gathered at Massachusetts General Hospital where the injured officer was reportedly taken. Officers directing traffic asked those who arrived in a panic: “friend or family?” A few officers wept openly as they hurried into the emergency room.

—Josh Dawsey and Jon Kamp contributed to this article.

SOURCE: online.wsj.com