Maria Acosta ran to her neighbor's house in St. Paul about 4:30 a.m. Thursday as flames engulfed a staircase that was the only exit for the second floor of a duplex.
"All of a sudden, it went, 'Whoosh!,'" Acosta said, recalling how fast the fire spread at the back of the building.
The first-floor tenant, Laura Haslach, escaped after being awakened by pounding on her back door. But she was horrified -- her daughter, Allison Haslach, and her daughter's fiancé and two young children were trapped upstairs.
"All I could think was, 'Please, don't let them die in a fire!'" Haslach said.
She reached for a hose, but it wasn't working. She threw a flowerpot at the couple's bedroom window, which was at the front of the house. Acosta grabbed flat, palm-sized rocks from her garden and pelted the window until the couple woke up about five minutes later.
Allison's fiancé smashed the window open. By then, other neighbors had gathered.
One neighbor called for a sheet to catch the tenants.
"No, no, no!" Acosta said. "Get a mattress!"