"Words fall short to describe the tragedy that took place this morning," Colorado Springs Police Chief Vince Niski said in a statement on Sunday. "From the officers who responded to the shooting to the investigators still on scene, we are all left incredibly shaken."

From a townhome community and a neighborhood park, to a hotel and a nightclub, these are the mass shootings that shook communities across seven states.

Phoenix

A group attending an event at the hotel got into an altercation that resulted in the gunfire, Cox said. All of the victims are believed to be between the ages of 18 and 22.

Cox told reporters there was more than one shooter, but investigators are trying to find exactly how many and what types of guns were used.

The shooting was an isolated incident and not a random act, she added.

Woodlawn, Maryland

Three people are dead and another was injured during a shooting at a townhome Saturday morning just outside of Baltimore, authorities said.

Investigators say the suspect lit his residence on fire and forced his way into his neighbors' home, where he then shot and stabbed them, according to the release. He shot two more neighbors as they came out of their home, including a 24-year-old who died, the release said.

The suspect was confronted by responding officers who ordered him drop his handgun, according to the release. He was then shot by officers and taken into custody after refusing, the release said, and later died in the hospital.

California

At least three people were killed and nine others injured in three separate shootings in California.

In Los Angeles, one person died and five others were injured in a shooting late Sunday night.

Officers found several fights happening in the parking lot of the club and surrounding area, according to the affiliate.

That same night, more than 400 miles away in Compton, police were in the area when they heard shots fired.

Newark

Two men and two women "were injured by gunfire," according to the tweet.

Police are asking anyone with information to call 1-877-NWK-TIPS to provide tips.

Milwaukee

The victims, ages 23 to 45, all suffered non-life-threatening injuries, the release said.

Two men have been arrested in connection with the shooting and charges will be forwarded to the prosecutor's office in the coming days, according to the release.

St. Louis County, Missouri

Two people are dead and three others injured after a shooting in a park in Kinloch, Missouri, on Friday night, St. Louis County Police said in a news release.

Williams said he was in the area for a "neighborhood celebration" when a truck pulled up and started shooting.

"It's just outrageous, it was crazy," Williams said.

Police said they did not find any victims when they arrived at the scene around 6:30 p.m., but later found that five people had taken themselves to the hospital.

Two of the men were pronounced dead at the hospital while the other victims suffered non-life-threatening injuries, according to the release.

The investigation is ongoing and police are asking anyone with information to call the St. Louis County Police Department.