Katie Reilly,Alana Abramson
Updated: Jun 14, 2017 3:36 PM ET

Five people, including House Majority Whip Rep. Steve Scalise, were shot early Wednesday morning in Alexandria, Va., when a gunman opened fire during a practice for an annual congressional charity baseball game.

Aside from the suspect, those shot and hospitalized were House Majority Whip Steve Scalise, Matt Mika, a lobbyist for Tyson Foods and the company's government relations director, Zack Barth, a legislative correspondent for Texas Rep. Roger Williams, who was shot in the leg, and a U.S. Capitol Police Special Agent Crystal Griner, who was shot in the ankle.

Scalise and Mika are in critical condition and required surgery. Barth was released from the hospital Wednesday, and Griner remained hospitalized as of Wednesday evening, but in good condition.

The suspect, who law enforcement identified as a 66-year-old James Hodgkinson of Bellevile, Illinois, died from gunshot wounds sustained during a shootout with law enforcement. The FBI, who said Hodgkinson had been living out of his vehicle in Virginia since March, is conducting an investigation into his motives.

In addition to those who who were shot, Williams, who dove into a dugout during the shooting, has a minor ankle injury. Another U.S. Capitol Police Officer, Special Agent David Bailey, was taken to the hospital for minor injuries, but has since been released.

Republican lawmakers, aides and operatives had convened for their daily early morning practice at the Eugene Simpson Stadium Park in Alexandria, Virginia. The Congressional Baseball Game, an annual bipartisan event that dates back to 1909, was one day away.

But less than 45 minutes later, Hodgkinson opened fire on the field. " Everybody yelled, 'he's got a gun! Run for cover!," Williams, who coaches the team, later recalled on Wednesday.

By 7:12 a.m., Alexandria police were on the scene at the park, joining the U.S. Capitol Police, who had already been on the scene to accompany the lawmakers. Law enforcement spent the next two minutes engaging in gunfire with Hodgkinson.

Although the police shot Hodgkinson at 7:14 a.m, inducing wounds that would ultimately prove fatal, he had still managed to send four people to the hospital with gunshot wounds, two of whom would remain in critical condition.

Scalise remains at the MedStar Washington Hospital Center, where he was undergoing surgery. "Prior to entering surgery, the Whip was in good spirits and spoke to his wife by phone," his office said in a statement. "He is grateful for the brave actions of U.S. Capitol Police, first responders, and colleagues."

Mika was also undergoing surgery; his family rushed to D.C. Wednesday afternoon to be by his side.

“It’s hard to contain the emotions," Alabama Republican Rep. Mo Brooks, who was at the baseball practice, said in an interview on CNN. "My adrenaline is raging, and of course, it’s never easy to take when you see people around you getting shot and you don’t have a weapon yourself, so you’re not in a position where you can help defend."

The shooting shocked lawmakers as well as the residents of the quiet neighborhood around the Alexandria Park, where baseballs lay scattered across the infield while police investigated the scene. Neighbors described waking up to the sound of gunshots, initially assuming they were just construction noises.

"I was shocked. I mean, my God, you don't expect that in your own neighborhood. You really don't," said Marion MacLean, a retired high school teacher who lives in the area. "This is a very peaceful neighborhood."

Hodgkinson had been upset that Donald Trump won the 2016 presidential election, his brother told the New York Times. He had volunteered for the presidential campaign of Democratic candidate Bernie Sanders, according to the Washington Post, which cited another campaign volunteer. Sanders said he was "sickened" by the shooting.

The FBI declined to comment when asked if Hodgkinson had a "vendetta" against Republicans.

But Rep. Ron DeSantis told Fox Business' Neil Cavuto that he and Rep. Jeff Duncan were leaving the field early Wednesday when a man approached their car and asked if the Republicans or Democrats practicing on the field. They responded it was Republicans and the man walked toward the field. DeSantis is confident that man was Hodgkinson, he told Cavuto.

Speaking shortly after the incident, President Trump, who cancelled his planned remarks at the Department of Labor, urged national unity and paid homage to those who were on the field and the courage of law enforcement. Trump made a surprise visit Wednesday evening to MedStar Hospital Center, where Scalise is still recovering

"Everyone on that field is a public servant: our courageous police, our congressional aides who work so tirelessly behind the scenes with enormous devotion, and our dedicated members of Congress who represent our people," Trump said in remarks Wednesday morning. "We may have our differences, but we do well in times like these to remember that everyone who serves in our nation's capital is here because, above all, they love our country."

Kentucky Sen. Rand Paul, who was at the baseball practice, also praised Capitol Police for their response to the shooting, saying it would have been a "massacre" if they hadn't been there. House Speaker Paul Ryan highlighted Griner and Bailey by name in remarks Wednesday, calling them heroes.

Williams said he thinks up to 25 people could have been killed had it not been for those officers.

The Republican members of Congress were practicing for Thursday’s Congressional Baseball Game at Nationals Park, a tradition since 1909 that pits Democratic members of Congress against Republicans. Proceeds from ticket sales go to charity. The game’s website describes it as “the only annual partisan showdown beloved by all and enjoyed by thousands. Every year, with a few interruptions, Senate and House members of each party team up to settle scores and solidify friendships off the floor and on the field.” The game is set to take place as scheduled on Thursday.

House and Senate Democrats, who were holding their own practice at a different baseball field Wednesday morning, stopped play to gather for a group prayer for their colleagues.

"We cannot let this be a victory for the assailant or anybody who would think that way,” House Minority Leader Nancy Pelosi said Wednesday, hailing sports as a unifier in a speech on the House floor.

"We are united in our shock," Republican House Speaker Paul Ryan said on the floor. "We are united in our anguish. An attack on one of us is an attack on all of us."

-Sandra Sobieraj Westfall and Jack Brewster contributed reporting.