Congressional staffer Zack Barth was in right field when a gunman unloaded dozens of bullets across an Alexandria, Virginia, baseball diamond Wednesday morning.

The shooter hit Barth in his left calf. Pumping with adrenaline, the 24-year-old raced to a dugout for cover.

"I was running for my life. I was bleeding pretty badly, but I was just trying to keep my head down," Barth said Thursday on TODAY, recounting the 10 harrowing minutes as he and a team made up of GOP lawmakers and other aides were attacked during their practice for a charity baseball game.

Barth's boss, Texas Congressman Roger Williams, said he was hitting ground balls on the third base side to congressional colleague Steve Scalise, the House majority whip, when a loud noise startled them.

"A lot of us thought it might have been a car backfiring," Williams said. "People were yelling, 'He's got a gun, get cover!'"

Williams said he standing about 20 yards from the shooter. He dove head first to the dugout, where he was joined by Sen. Jeff Flake of Arizona and Rep. Mo Brooks of Alabama. An injured Barth came barreling towards them. Brooks stripped his belt off and the men used it as a tourniquet on Barth's leg, Williams said.

Rep. Roger Williams, R-Texas, is transported away from the scene by emergency medical service personnel. Alex Wong / Getty Images

Meanwhile, two Capitol Police officers who were already at the scene exchanged gunfire to stop the shooter, who ended up hitting one of the officers, as well as Scalise and a lobbyist. The other officer suffered a minor non-gunshot injury to his ankle.

The suspected shooter — later identified as Illinois man James Hodgkinson — died from his injuries after police returned fire.

Related: Capitol Police Officers Hailed as Heroes After Baseball Practice Shooting

The officers were at the practice because Scalise is granted security detail as a high-ranking member of the House.

Williams suffered a sprained ankle as he took cover.

"We had baseballs and bats to defend ourselves," Williams said on TODAY. "The Lord worked yesterday, he saved us. We're grateful for that and grateful again to the Capitol Police who saved us."

"I'm very blessed to be alive," Barth said, crediting the officers as well. "Without them, there would be tremendous loss of life and I probably wouldn't be talking to y'all."

Scalise, who was shot in the left hip, remained in critical condition Thursday with further surgery planned. On Wednesday night, President Donald Trump and first lady Melania Trump visited the Louisiana congressman at his bedside, crediting him as a "real fighter."

Just left hospital. Rep. Steve Scalise, one of the truly great people, is in very tough shape - but he is a real fighter. Pray for Steve! — Donald J. Trump (@realDonaldTrump) June 15, 2017

Vice President Mike Pence and his wife, Karen, visited his hospital Thursday.

Karen & I just left @MedStarWHC. Thanked docs & staff. Keep @SteveScalise, Officer Griner & all involved & their loved ones in your prayers. pic.twitter.com/JcKwTMLPDH — Vice President Pence (@VP) June 15, 2017

Matt Mika, a lobbyist for Tyson Foods and a former congressional staffer, remained at George Washington University Hospital where his family said he can't breathe on his own and will need additional surgeries.

Mika was shot multiple times in his chest and arm, and suffered "massive trauma," his family added, but he remains alert and is "communicating through notes."

"We understand he is lucky to be alive and we owe it to these amazing individuals and Matt's fighting spirit and grit," the family said in a statement.

Authorities are investigating a motive for Hodgkinson's apparent rampage on the lawmakers. Before the shooting, he allegedly asked people gathered there, "Are these the Republicans or the Democrats?"

Officials say the suspected shooter came to Virginia in March and had been living out of his van. Social media accounts appearing to belong to him feature a history of anti-Republican and anti-Trump posts.

The charity game between Republicans and Democrats on Thursday night is scheduled to go on.