On Sunday evening, more than 400 people were injured [VIDEO] and 50 killed at a concert at the Route 91 Harvest Festival in Las Vegas, Fox News reported. Stephen Craig Paddock, 64, of Nevada, is believed to be the gunman.

How did it happen?

The gunfire started around 10 p.m. while Jason Aldean, the final performer of the festival, was on stage. The singer, at first, thought that the gunshots were firecrackers until he realized the truth.

The gunman had checked into a hotel room with the window to the concert place beforehand. In the end of the concert, he fired down to 40,000 people from his room on the 32nd floor of the Mandalay Bay Resort and Casino.

He was shot by Las Vegas police officers, who used an explosive device to enter the closed room and kill Stephen Paddock. The police also found various weapons, including ten rifles, in the hotel room.

Details of the incident

Marilou Danley, Paddock's roommate, was not involved in the incident, detectives reported. Two police officers from Las Vegas Metropolitan Police Department got injures during shooting.

As the federal officials stated, the shooting is not connected with international terrorism. The motive for the shooting is not clear.

According to the witnesses, it was extremely hard for the fans to get out of the dangerous place. When the mass panic started, thousands of people rushed away.

According to the statement from McCarran International Airport, situated not far from the concert place, an airport perimeter fence was breached by the running fans.

The airport staff evacuated the people. On its official Twitter account, Mandalay Bay Resort wrote: "We’re grateful for the immediate actions of our first responders."

On his Instagram page, Jason Aldean, who was on the stage when the shooting started, wrote: "Tonight has been beyond horrific," adding his post with the hashtags "#heartbroken #stopthehate," ABC News reported.

Retired FBI special agent John Iannarelli noted that the shooting was "obviously well-planned," adding that the weapons used by Paddock were expensive.

The FBI and the local police are investigating the incident. Their work will include the reports of friends and relatives. The gunman's computers and phones are being checked now.

On his official Twitter page, President Donald Trump wrote his "condolences and sympathies to the victims and families of the terrible Las Vegas shooting."