(CNN) - When a shooting erupted at Marjory Stoneman Douglas High School in Parkland, Florida, the first thing some students did was contact their parents.
Those parents' voices could be heard on the line in 911 calls released by the Broward County Sheriff's Office on Thursday.
One woman's voice cracked as she read the dispatcher a text message from her son: "Shot, shot, shot. Mom. God." Another woman told her daughter to play dead.
At least one person called from inside the school. "Marjory Stoneman Douglas High School is being shot up," the caller whispered.
The Broward County Sheriff's Office released a sampling of the calls operated received on February 14. Here are some excerpts:
'You need to play dead'
One person called 911 on behalf of a mother who was on speaker phone with her daughter.
Caller: "There's no place to hide ... they're crouched (under) the window."
Mom: "Oh my God, I love you. It's the cops?"
Mom: "Can you play dead?... If he shoots, you need to play dead. If he shoots, play dead."
Minutes later, the caller says the police were escorting the students out of the classroom.
Caller: "Thank you for all your help. I hope this turns out to be not as bad."
Dispatcher: I hope so, too. ... Oh my God."
A call from inside the school
Someone called from inside the school and whispered to the dispatcher.
Caller: "Someone's shooting up the school at Stoneman Douglas."
Dispatcher: "I'm sorry, I can't hear you. What's happening?"
Caller: "Marjory Stoneman Douglas High School is being shot up."
Dispatcher: "Are you at the school?"
'She's behind the desk right now'
Caller: "My daughter just texted me from school, she's at Stoneman Douglas ... and she says there's an active shooter."
Caller: "She says she's behind the desk right now but the shots were close."
The operator stayed on the call until the woman received word that her daughter was safe.
Caller: "The police are here ... there were three shots in her room, oh my God, oh my God."
Dispatcher: But she's OK, right?"
'Shooting in Douglas High School'
One mother told the dispatcher her son called her to say "there is shooting in Douglas High School."
Dispatcher: "And they said it's happening in the school?"
Caller: "He text me ... and he said 'shot, shot shot. Mom. God.' "
Dispatcher: "There are multiple police officers and fire rescue on the way out there, okay."
'He's locked in the math class'
Dispatcher: "Ma'am, where is your son inside the school? What room number is he in?"
Mom: "He said he's in one of the math classes."
Dispatcher: "Do you know what room number that is?
Mom: "I asked him, he said he's locked in a math class."