A shooting at UCLA Wednesday morning left two people dead, according to the Los Angeles Police Department. The campus was promptly placed on lockdown, with local authorities treating it as an active shooter situation.

The victim of the murder-suicide has been identified as William S. Klug, a professor of engineering, according to ABC 7. His friends told the network Klug was a married father of two who also coached Little League baseball and soccer. 

The gunman has reportedly been identified as student Mainak Sarkar, CBS News reports. Sarkar used a 9mm semiautomatic pistol to murder Klug inside an office before killing himself.

The shooting occurred inside Engineering IV, a building near the center of campus, according to UCLA. Both FBI and ATF personnel responded to the shooting, sending "hundreds" of officers to the Westwood campus around 10:30 a.m., local time. Police thoroughly searched the campus, which covers more than 400 acres, using a "grid-by-grid" system. The suspect, according to the Times, was initially described as a "6-foot-tall white male dressed in all black."

LAPD chief Charlie Beck confirmed the shooting was indeed a murder-suicide, according to AP. The identities of the deceased have still not been released. The campus reopened around 12:30 p.m. local time, with Herren confirming in a press release that "hundreds" of law enforcement officials had responded to the scene following the initial 911 call around 10 a.m.

"We have a lot of resources here that we're dedicating to ensure the safety of the campus community," Herren said. "It is something that we have trained to do. So when our officers arrived on scene they immediately began putting teams together ... to help those who have been injured and also search teams to look for suspects who may [have been] in the area​."

Joey Rehermann, a 20-year-old physiological science major, said he was walking by Engineering 4 around the time of the shooting, and saw students outside staring at the building. As Rehermann continued walking to class in nearby Young Hall, he saw the same students sprinting, which prompted him to run into his classroom. He said he didn't hear any gunshots.

Most of the students inside the lecture hall got an alert from UCLA telling them a police investigation was underway at Engineering 4 and to stay away from the building. A subsequent alert notified them of the shooting and lockdown, and about 100 students packed into another room connected with other lecture halls.

"We were getting a lot of false reports about what was going on," Rehermann told Complex. "People were telling us there were maybe four shooters. We weren’t sure what was really going on, so we were pretty scared."

After an hour, Rehermann said, some students near a window in the room spotted movement. They turned off the remaining light that was still on and crowded toward the back of the room. Shortly after police armed with assault rifles, helmets, and other protective gear came in and evacuated the room.

"Everyone was dead silent," Rehermann said. "I was really scared. I took my backpack off, and I put it over my chest because I had my laptop in there. I didn’t know what was going to come in. A lot of people did that. We weren’t sure what to expect. Once people realized it was the police, I calmed down. I felt pretty secure."

Police told them to put their hands over their head and led them out through the hallway, according to Rehermann. One officer checked the students bags. Once outside, they were lead further East from Engineering 4 to Parking Garage 2. The students remained there until UCLA said the lockdown was over.

"There were police with us the whole time," Rehermann said. "Then a lot of reporters came in, so I felt pretty safe. Once they texted us saying the lockdown was clear, everyone emerged from where they were hiding, and the campus flooded."

Ryan Cosgrove, a 20-year-old poli-sci major, was outside Royce Hall when he was first alerted to the shooting by UCLA at around 10 a.m., local time. Cosgrove told Complex he had just finished a final exam and retreated back into the building to find a safe space. He then hunkered down in a professor’s office, where they closed the blinds, turned off the lights, and locked the door. At first, only Cosgrove and the professor were in the office, but around 30 people eventually joined them. Some of the students later left for a larger room, bringing the number down to about 10. 

"It was standing room only," Cosgrove told Complex. "Everybody seemed pretty calm. No one was hyperventilating or really freaking out. Some people were a little more on edge when they told someone to turn off their phone or keep more quiet. There was some tension in the air, but for the most part everyone stayed calm."

The students spent the time texting friends and parents, letting them know they were safe, and monitoring the news via live streams, Facebook, and group chats. At 12:17 p.m. students were given the all-clear by the school. And after waiting a few more minutes, Cosgrove and his peers made their way outside.