NEW: Four people are dead and at least 13 others injured after a man crashed into a crowd outside a building in Tampa, FL
Tampa police arrested 22-year-old Silas Sampson on multiple charges after the deadly crash
Officers spotted two vehicles racing before Florida Highway Patrol troopers joined and tried a PIT maneuver
The vehicle sped down busy 7th Avenue, lost control, and crashed
More than a dozen people were hit outside a business
Three pedestrians died at the scene, and a fourth died at a hospital
Officials said 13 others were injured, with conditions ranging from life-threatening to minor
Some victims may have gone to the hospital on their own, raising the total to as many as 17