Part of Harrison Avenue in the South End remained closed Thursday afternoon after a steam pipe burst overnight.
The pipe blew early in the morning, sending a steady stream of steam and asbestos into the air and covered the road and cars parked nearby.
Boston Puboic Health says the amount of asbestos detected in the air in the dirst is well below acceptable levels.
Three years ago, there was a similar incident on Otis Avenue. The pipe rupture led the city to ask Tri-gen, the company that operates the steam pipes, for a system-wide review. Tri-gen says the review found the system was structurally sound.