Red Line subway commuters suffered serious delays yesterday morning when fires, falling ceiling tiles and a sick passenger immobilized six trains during a 90-minute period, Metro reported.

The tie-ups began at about 7:30, when a trash fire was reported in a tunnel near Judiciary Square. Firefighters found the flames already out and service was resumed.

At 8:15, Metro held a train at Farragut North while an ambulance was called for a male passenger who appeared to have suffered a heart attack. The train blocked the track for 26 minutes, forcing Metro to use the single open line for traffic in both directions.

At 8:45, a train was immobilized at Judiciary Square after one of its electrical cables caught fire and began emitting smoke. Power was shut off on both tracks as a precaution. Technicians finally removed the train from the station at about 9:20.

Shortly after that incident, tiles fell from the ceiling at the south end of Farragut North. Metro personnel cleared passengers from a train and used it to look for further damage in the tunnel.

In addition, two other Red Line trains were taken out of service during the morning after they gave off smoke, which is often associated with brake problems.