It happened just before 4:00 p.m. at the Cranston Hall Apartments in the 3300 block of Old Capitol Trail in Prices Corner.
Neighbors looked out their windows to see the family of four injured when lightning struck the tree they were sitting under.
A 30-year-old man, his 28-year-old wife and their sons, ages 7 and 1, were huddled under an umbrella when the bolt hit.
"They were just chilling under the tree, soaking up the nice day like they always do, chit chatting, shooting the breeze," said witness Billie Webb.
There was no visible damage to the tree from the ground, but emergency officials say it appears the lightning struck the top of the tree and sent down the shockwave.
Neighbors say the storm moved in very quickly.
"It all happened in five minutes, you know. A little bit of rain and then 'bang bang.' I mean, it sounded like a machine gun, pow pow. That was it, that quick," said witness Ron O'Neal.
Residents believe if one of the family members had been holding on to the metal rod of the umbrella this scene would have been much worse.
As the father returned home late Friday night a cousin of the victims, Irene Hernandez, said everyone is relieved that it wasn't worse.
"Everybody is happy right now. They just received phone calls and they're happy the four of them are okay. Actually there are five because she's pregnant, so they're fine," said Hernandez.
A very similar incident happened earlier this week in Wildwood, New Jersey, when four family members - including a pregnant woman - were hurt after lightning struck as they huddled under an umbrella.