At least 12 people were killed and more than 60 were injured in shootings across seven states overnight, including three separate incidents in a Dallas entertainment neighborhood where four people died.

In Dallas’ Deep Ellum neighborhood, three shootings killed at least four people and injured 15 more, Dallas Police Chief Daniel C. Comeaux said. A preliminary assessment indicated the shootings were not connected, he said.

Some victims took themselves to hospitals, and casualty numbers could change, Comeaux said at a news conference.

A witness described chaos interrupting a night of Halloween revelry.

“Right after one shooting, you would hear another shooting, and you would see all the police officers take off running to the next scene,” Jessica Gamboa told NBC News. “It was a scary and unbelievable night.”

In Birmingham, Alabama, one person was killed and eight others were wounded in a shooting outside Legion Field after Saturday night’s Magic City Classic football game. Birmingham Police Chief Michael Pickett said most spectators and families had left the stadium grounds, but the gunfire erupted nearby, where vendors were set up along Graymont Avenue. He said he was “very grateful that more people weren’t injured.”

The circumstances remained unclear. One person was detained and taken to police headquarters for questioning, and “multiple weapons” were found and secured, a police spokesperson said.

The annual game between Alabama State and Alabama A&M, historically Black universities and archrivals, has been played for more than 100 years. Nearly 70,000 fans attended Saturday’s game.

Two University of Colorado-Boulder students were shot, one fatally, at a house party in Boulder more than an hour after police responded to the house to address a noise complaint, police said.

Police left the scene after shutting down the party shortly after 10 p.m., taking one person who was extremely intoxicated on a hold. Another call came in around 11:30 p.m. to report a shooting, Boulder Police Chief Stephen Redfearn said at a news conference.

Two 19-year-olds were found with gunshot wounds at the home, and one died after being transported to the hospital, Redfearn said. Two people of interest are being sought in connection with the homicide.

In Jacksonville, Florida, a 17-year-old girl and a 20-year-old man were fatally shot in a pair of unrelated shootings at Halloween parties that left 11 others with injuries.

The girl was an unintended victim in a crowd waiting to enter a party around 1:45 a.m., police said. Investigators believe there were two gunmen. The man was at a house party when a fatal fight broke out, police said. He died at a hospital.

In Bloomington, Illinois, a 19-year-old woman died and seven were injured in a shooting near Illinois Wesleyan University. Police have not identified her, pending notification of her family.

In Jackson, Mississippi, a man and a woman were fatally shot and two others were injured at a nightclub, police said. One man was killed and several others were injured in a shooting before 2 a.m., according to local police.

Six people were also injured, none fatally, in a shooting near the University of Delaware in Newark, Delaware. Police are investigating. (NBC News)(